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Eagle River Area: Tennessee Pass to Dotsero

(U.S.G.S. Bulletin 707, 1922)

North of the tunnel [at Tennessee Pass] the railroad is at the headwaters of Piney Creek, down which it winds and twists to maintain an easy grade to the main stream, which heads on the flanks of Homestake Peak, On the west. This valley is generally covered with forest except near the railroad, where the trees have been cut for use in building the railroad and in working the mines. It is now a part of the Holy Cross National Forest (See sheet 4).

Like most mountain valleys that stand at a high altitude the valley of Piney Creek is broad and has gentle slopes. The old roadbed of the narrow-gage line, which crossed the summit of the pass, may be seen on the left of the present road, several hundred feet above it. The old line made a great detour to the west into the main valley, and its bed joins that of the present line at the station of Mitchell. Few rocks can be seen in place, but the tunnel at the pass was driven in granite, which is exposed also from place to place in cuts on the railroad. Just below Mitchell the stream has cut a rugged trench in the granite on the east side of its valley, upon which it had been crowded by a great mass of boulders and clay pushed out by a glacier that came down from the west. This glacier came at least as far as the creek, and at times the ice probably turned northward and followed the creek for several hundred yards. The conditions here resembled those that prevailed in Wildhorse Canyon, already described.

Below this point the stream has cut a deep gorge in its rocky floor, and its descent is so rapid that the railroad can not follow it, but climbs down more gradually along the west wall of the canyon. The old narrow-gage track swung to the east, making a broad loop up the East Fork of Eagle River, and then went northward to Pando, on the level floor of the old lake basin, now called Eagle Park. This grade is now utilized by the automobile road that in a general way parallels the Denver & Rio Grande Western Railroad from Leadville to Grand Junction.

In the vicinity of Eagle Park the granite is overlain by sedimentary bedded rocks that were laid down countless ages ago as sand on the shore of a sea. Since that time they have been crushed in the movements in the crust of the earth that have raised up the mountains. They have been permeated by waters bearing silica in solution until all the pores of the sandstone have been filled with silica or quartz (quartz is a form of silica) and the rock has become a glassy white quartzite. This rock crops out nearly parallel with the railroad and dips from 10 to 20 degrees E. It may be seen in the mountain side on the left nearly 400 feet above the railroad, and its nearly horizontal beds are on the opposite side of the valley about 150 feet above the creek. This mountain side is really the eastern slope of the great Sawatch uplift, or, as it is frequently called, the Holy Cross Mountains, which lie west of the railroad. The mountain slope on the other side of the valley is composed mainly of rocks that overlie the quartzite, and if a trench were cut from the top to the bottom of the slope the rocks would appear as shown in the figure.

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Near milepost 286 the traveler has an unobstructed view to the east (right) up the valley of the East Fork of Eagle River almost into Fremont Pass. The width of this valley suggests that it has been occupied by a great river of ice that originated in the high summits of the Mosquito Range north of Leadville and flowed down Eagle River valley to a point where the melting exceeded the supply of ice from above, but the region has not been examined carefully enough to determine this point.

Pando Area

In descending the west wall of the valley the traveler may look down upon the level surface of Eagle Park, and one of the features that may attract his attention is the crooked course of Eagle River, which wends its way down the valley in many bends or meanders. Courses so crooked are not limited to streams in mountain' regions but are characteristic of streams that flow on flat surfaces with a grade insufficient to enable them to straighten their channels. The cause of the flat surface here was a dam formed by a glacier in the valley at Pando. In the pond above this dam mud accumulated, and when the ice disappeared the valley was left with a flat mud bottom, which has since been covered with a thick layer of turf.

A little below this point, at the signal tower of Deen, is the beginning of the double track that extends from that place through Eagle Canyon to Minturn.

The railroad follows the outcrop of the bedded rocks, which maintains, at least as far as Pando, about the same relative position as when first seen-that is, about 500 feet above the valley floor on the west and 100 to 150 feet on the east. Just after passing milepost 288, half a mile above Pando, the traveler may see on the east (right) a low ridge of gravel, which extends across the valley and which is thought by some geologists to have constituted the terminal moraine of a very old glacier that once came down Homestake Valley from the southwest, though the writer thinks that it was more probably the terminal moraine of a great glacier that came down to this point from Fremont Pass; but, as already stated, the region has not been examined with sufficient care to justify a definite statement on this subject. The trench that the stream has cut in the, moraine has been filled by an artificial dam, and the pond above the dam is utilized for making ice.

At Pando, the railroad turns abruptly to the right and follows the river across the broad valley to its eastern wall. The reason for this abrupt change in the course of the railroad from one side of the valley to the other is that half a. mile below Pando the valley, although broad, is almost completely blocked by a great mass of gravel and boulders, which was brought down by a glacier that once descended Homestake Creek, on the west, but pushed a tongue of ice into this valley. The material brought in by this glacier obstructed the drainage of the valley so much that the river was forced against the cast side, and the railroad has followed ,the pathway kept open by the stream. The course of Eagle River has been greatly affected by this glacier and by the morainic material which it deposited.

As the railroad curves about the terminal moraine that marks the lower limit of the glacier the traveler may catch, far to the west (left), a fleeting glimpse of the Mount of the Holy Cross (13,986 feet), so named because the snow on its cast slope clings throughout the summer in a great vertical cleft that extends nearly the whole height of the mountain and in a horizontal cleft that crasses the vertical cleft, the two together having the form of a cross. The Mount of the Holy Cross is familiar to many persons through Moran's painting, which has been reproduced extensively in colored prints and postcards. It is doubtful whether from Pando the traveler can see, even in the best weather, more than the crest of the peak, but farther along the road, near Minturn, he may obtain a somewhat better view of this well-known mountain. The cross and the mountain that bears it are well shown in Plate LIII.

In some places the rock beds are bent upward and the underlying granite appears in great irregular masses, but beyond such bosses, which continue only for short distances, the quartzite takes its accustomed place at railroad level.

Redcliff Area

The course of the river is nearly due north to the junction with Weary Man's Creek, which comes in from the east. The combined stream turns abruptly and flows west until it joins Homestake Creek and is again in its rightful valley. At the sharp turn from north to west is situated the mining camp of Redcliff, which is also the county seat of Eagle County. This valley was the route of an exploring party under the command of Capt. (afterward Gen.) John C. Fremont, and a flag on a rocky eminence on the right of the railroad in Redcliff is said to mark the site of an engagement with the Ute Indians in one of his expeditions between 1842 and 1845.

Several mines are in operation in the vicinity of Redcliff, and others may be seen in the canyon between Redcliff and Minturn. (See Pls. L, B, and LIV.) Some of these mines have found gold in the granite near the railroad track, but most of them are operating in the Leadville limestone at the top of the canyon wall and the products are silver, lead, and zinc. At the station at Redcliff the granite may be seen on the right, and above the granite, towers a great cliff of quartzite, making an imposing entrance to Eagle River canyon, which begins at this point and extends down the stream for a distance of 4 miles. Overlying the quartzite, but hardly visible from the station, is the outcrop of Leadville limestone, marked everywhere by mines and prospect pits. Above the limestone may be seen here and there ledges of red rock belonging to the upper part of the Carboniferous-the same formation that is so conspicuous about Howard and Salida.

After leaving the station at Redcliff the traveler has just about time to turn in his seat and see the mouth of Homestake Creek on the south (left). Eagle River once occupied this valley, as already explained, but was turned out of its course by the glacier that came down the creek valley from the high mountains on the south. The glacier did not quite reach the site of the railway below Redcliff, but at the time of its greatest extension its front was only a few hundred yards away. Below the mouth of this creek the railroad follows the river through Eagle River canyon, which is not so deep as many gorges cut by Arkansas River on the other side of the Continental Divide, though for narrowness and picturesqueness it is excelled by few.

Belden Area

The stream, which has here become a river, tumbles down through the narrow gorge, dashing its spray over the great boulders that obstruct its pathway. The walls of the canyon rise in jagged pinnacles to a height of 400 or 500 feet and on the east are capped by banded quartzite, the projecting points of which look like ruined castles perched on the rocky walls. Mining has been carried on in this canyon and on the, surrounding mountain slopes for many years, and the walls are honeycombed with old prospects and tunnels driven in search of gold. The ores obtained in the limestone above the canyon were lowered to the railroad on inclined tramways or aerial cable lines, the remains of which may be seen along the east wall at points where an unobstructed passageway could be obtained from the head-house, which seems to have a precarious footing on the rocky slope, down to the railroad. For some distance all the mines seem to have been abandoned, but near milepost 296 the river swings to the east. and the sedimentary rocks, which dip in that direction, are much lower than they are farther up the stream. Here there are several large mines (see Pl. L, B), and the mining town of Gilman has been built on a rocky point that projects into the canyon from the east at a height of several hundred feet above railroad level. The mines are in the Leadville limestone, which lies above the precipitous walls of quartzite and granite, and the traveler may be able to see some of the ore being lowered to a mill in the bottom of the canyon. The ore is crushed in this mill and partly separated from the rock with which it is associated and is then shipped to some smelter for reduction to the metallic state. At Belden the quartzite is about 100 feet above the railroad and has a thickness of 250 to 300 feet. It is overlain by the Leadville limestone, which shows at the top of the canyon wall.

Eagle River canyon is so narrow that in building the second track the Denver & Rio Grande was forced to use both sides of the river and even there had to tunnel through many of the projecting points of rock. The westbound track follows the east side of the canyon and the eastbound track the opposite side.

For a short distance below Belden the canyon continues narrow and rugged, but its course is more and more toward the east, and the result is that the quartzite steadily approaches railroad level downstream. About half a mile below milepost 297 the quartzite reaches railroad grade, and a short distance below it passes beneath the stream and is lost to view.

Just before reaching Rex siding the traveler may see on the west (left) a ridge of loose boulders, which seems almost like a dam thrown across the valley of Eagle River. Doubtless he has already learned to recognize such an accumulation of boulders as a moraine that was pushed out by a glacier from some side valley. This moraine was built by a large body of ice which descended Cross Creek from the high peaks of the Holy Cross group of mountains. The boulders were carried entirely across the valley of Eagle River, showing that the ice filled the valley to the foot of the slope on the east side. The glacier expanded when it reached Eagle River, so that its extremity must have resembled a fan, and it covered the area on which the railroad has been built for a distance of 21 miles. One of the great blocks of gneiss which it carried to the foot of the slope on the farther side may be seen on the east (right) of the track near Elk Creek. It is 40 feet long and 25 or 30 feet wide, and its top stands 12 feet above the ground.

Cross Creek is noted for the, peculiar forms that were produced along it by the passage, of the glacier over its granite bed. As the glacier found the floor of the granite canyon somewhat irregular its principal work was to round off and polish the projecting knobs. The rounded masses of granite in this canyon are called 11 roches moutonnes " (rosh moo-ton-nay'). This name has been applied by French geologists to such rounded rocks on account of their fancied resemblance, when seen at a distance, to the backs of sheep.

At Rex siding the top of the quartzite is at railroad level, and the Leadville limestone may be seen on the left, where it forms several knobs. Its color is light blue, and it is easily distinguishable from the quartzite, which has a yellowish tone. As the railroad swings to the east and the rocks dip in the same direction the Leadville limestone soon disappears below the bottom of the valley, and the only hard rocks in sight are the Carboniferous sandstones and shales, which give to the slopes on the east (right) their banded appearance.

One of the most noteworthy features of this part of the Denver & -Rio Grande Western Railroad is the Mount of the Holy Cross This peak stands near the head of Cross Creek, but unfortunately no. good view of it can be obtained from the train. Near the mouth of Elk Creek, however, a fleeting glimpse of the mountain may be had, if the traveler is on the alert and looks in the right direction. As the train swings eastward and approaches the mouth of Elk    Creek the traveler, by looking back on the west (left) may see high rugged peaks coming one by one into view. Mount Jackson may be seen by looking up Cross Creek, but the one peak which he desires to see more than all others is hidden for a long time by the high plateau on the south side of the canyon. Finally, however, after crossing Elk Creek, which comes in from the east, when the train is near milepost 300 and just before it passes behind a ridge on the left, the traveler may catch a glimpse up the creek valley of the Mount of the Holy Cross, but even here the cross itself is not well shown. Very few persons who have passed over this road have been able to identify this famous peak, but if the traveler will look as directed he can certainly see it unless the atmospheric conditions prevent a view of any of the high mountains.

Just after milepost 300 is passed the moraine that marks the other limit of the Cross Creek glacier appears across the river as a sharp and distinct ridge which curves parallel with the railroad, and a good view of its tree-covered slopes may be had from the train. This moraine is composed of sand, clay, gravel, and boulders brought down by the ice from the high mountains on the west, and the glacier that brought this great mass of material marked the last stage of glaciation (Wisconsin) that affected North America; but half a mile beyond milepost 300 there is on the west (lef t) another ridge or moraine that is rudely parallel to the other ridge just described, but sharply distinct from it. This outer moraine was evidently formed long before the last glacier occupied the valley, for its slopes are more affected by the weather, and as it is outside of the other moraine it must have been formed earlier or else the ice would have demolished the inner ridge, which now is the more conspicuous of the two. The existence of this older moraine shows clearly that glaciers were formed in these mountains in at least two distinct epochs of time, one of which was much earlier than the other.

The rocks that are so well shown in the mountain slope on the east (right) are supposed to belong to the lower part of the upper Carboniferous or, in other words, to have been formed at the same time as the earliest of the great coal beds in the Appalachian region and the Mississippi Valley. In the Rocky Mountains some coal beds have been found in these rocks, but most of them are too small or too impure to be worked profitably. The lowermost of these formations is the Weber shale, which lies directly above the Leadville limestone but which is so soft that it makes no showing at the surface. Above the Weber shale lies 200 or 300 feet of sandstone and shale that have a strong reddish tint, and above this for 1,000 feet or more the rocks consist mainly of light-colored sandstone separated by layers of shale. On account of this alternation of rocks the hillside appears to be ribbed horizontally by beds of white rock.

Minturn Area

As the railroad curves back toward the west the river cuts into the Leadville limestone. The rock is first seen near milepost 301, but it rises steeply and at the milepost is 30 feet above the track Here the direction in which the beds of rock trend or strike begins to be affected by the northward plunge of the Holy Cross anticline, so that the Leadville limestone, instead of becoming higher and higher as the train descends the valley, dips down the stream, and before the train reaches Minturn. the beds are below water level.

The town of Minturn. is built on a broad flat valley bottom in which no hard rocks are exposed, but a mile below the station the same beds of rock which before were seen only in the cliffs on the east form the mountain side on the west, showing that the beds of rock are swinging more toward the west than they do farther up the river. The red sandstone that was so conspicuous above disappears on the right about the mouth of Gores Creek. This creek is a clear mountain stream that heads in the high peaks of the Gore Range on the east, some of which may be seen by looking directly up its valley. The stream is noted for the fine fishing that it affords and that tempts many anglers to come here to try their luck. The double track which begins above Redcliff ends just below the bridge over Gores Creek.

At the point where the red sandstone and shale pass below railroad level near Gores Creek the cliff on the right is composed of the overlying light-colored sandstone and interbedded darker shale. At the mouth of the creek these beds dip about 300 NE. A short distance below the mouth of the creek the river bends sharply toward the cast, and in so doing it cuts more directly across the hard ledges of sandstone, which compose the bulk of the formation. As these rocks are harder than those either above or below, the canyon cut by the river is narrower and more rugged than it is in the vicinity of Minturn. or below that place, Where the beds are much softer. After making a great curve to the right the sandstones (Weber formation) abruptly come to an end. As the train passes this point the traveler may not fully realize why they terminate at this place, but the map will show him that their disappearance from the cast side of the river is due to the fact that they swing across the stream, although they do not show in the hillside on the west. If the traveler looks back after passing down the valley a mile or so he will see these beds on the east side of the valley dipping about 45 degrees NE. and reappearing on the west side, as described above. The beds that overlie the sandstone are very soft and consist mostly of clay or shale with here and there a more sandy layer that makes a ledge along the hillside. The beds are so soft that they have been worn down into comparatively low hills, at least near the river, and the slopes are everywhere round and gentle. These rocks are the same as the variegated sandstone and shale at Leadville, which have been called the Maroon formation.

Avon Area

Immediately below the mouth of the canyon the river bottom, which expands to a width of about half a mile and holds it for a distance of several miles, is strewn with boulders brought down by the stream. These boulders extend for about half a mile, and below that point the valley, although narrow, is well irrigated and farmed. The hills on the west side of the valley bear no resemblance in form or color to those on the east. They are dark and their surf aces are hummocky, as if composed of soft material that has slid down the hillside until it resembles a gigantic moraine. The reason for the peculiar appearance of this hillside is not apparent until the traveler has passed the little village of Avon and has looked back on the other side of the hill. The rocks here are well exposed by the cutting of the stream that comes down out of the high mountains on the west. At the base they consist of the ordinary country rocks with which the traveler is already familiar. Above these rocks lie some darker ones, composed of volcanic material that was long ago washed down to this position from a lava flow. This material, which is soft and easily washed by the rains, has slumped down the hillsides until it has given the surface a general hummocky appearance.

The valley at Avon is nearly a mile wide, and in summer it presents a beautiful appearance, with field after field of grain rippling in the wind and here and there a well-kept farmhouse peeping from a grove of cottonwood trees. The farms extend about a mile below the village to a point where the bluff on the east side swings in against the river, cutting off the farming land and rendering the valley rough and broken. The railroad, which has been forced to follow the river along the west (left) side of the valley, swings to the right in a broad curve at Edwards siding, just beyond milepost 312, and continues on that side for some distance. As the railroad is high above the river and skirts the bluffs along the east side, the traveler has an unobstructed view of the full sweep of the valley. A large valley comes in from the southwest (left), and soon the high peaks of the Holy Cross Range burst into view. The view near milepost 313 is one of the most attractive on the road, especially in early summer, when the summits are still covered with the snow of the previous winter, or in early autumn, when they are white with the first snow of the season. One can look across the grassy bottom of Eagle River, dotted with herds of cattle, to the ranches on the opposite side, where field after field of grain or hay stretches up the side valley as far as the eye can see and even climbs the opposite slope to the highest terrace. Here and there ranch houses are embowered in groves of trees, and the white schoolhouse, with its bright-red roof, gives a touch of color to the pastoral scene. The green fields, especially when the afternoon shadows begin to lengthen, look like velvet, and one would have to travel far to find a landscape more beautiful.

In the movements that have, raised the mountains the soft rocks have been crumpled and folded or crushed and broken in a very complex manner. Just beyond Allenton siding, beyond milepost 314, the beds of rock are magnificently exposed on the east (right), for here an old bend in the river threw it against the foot of the bluff, where it washed away all loose material. Here the beds of rock stand nearly vertical, but within a short distance they show a tendency to flatten and pass with slight dips under the river, which here swings sharply to the right. The traveler can see that the rocks here are prevailingly soft and that only here and there thin beds of sandstone stand out like giant ribs on the face of the cliff. The colors of the rocks are variegated, but there is enough red and deep brown in them to give the hills a warm tint.

Half a mile beyond milepost 315, at the crossing of a small creek which enters the river from the right, the base of brilliant lightred sandstone is exposed. This sandstone is Triassic in age and is much more showy in color than any other rock which the traveler has seen since he left Canon City. On account of its striking color attempts have been made to utilize it as building stone, but generally it is so easily affected by the weather that in a few years the corners are rounded off and even great holes are etched in the solid blocks. Where first seen these beds dip about 45 degrees W., but the dip flattens in a short distance to about 25 degrees W. Beyond milepost 316 the top of the bright-red beds may be seen on both sides of the river. On the right they extend down the hillside in a great curve, but on the left they run along the face of the bluff with only a slight dip downstream.

The rocks that overlie the bright-red sandstone are variegated in color but are predominantly green and maroon. They make up what is called the Gunnison formation, so named from its outcrop in the valley of Gunnison River. The upper part of this formation is without doubt the same as the Morrison formation on the east side of the mountains, but its lower part probably includes rocks that are not found on that side. The Gunnison formation here contains much soft shale and clay but includes also some beds of resistant sandstone. At this place the formation has been so much crushed that its thickness can not be estimated, but at other outcrops in this vicinity, where it is undisturbed, it is about 220 feet thick.

Above the Gunnison formation lies the Dakota. sandstone, which crosses the track near milepost 317. This sandstone marks the base of the Upper Cretaceous and is one of the most persistent and widespread formations of the Rocky Mountain region. It extends from northern Wyoming to central New Mexico and from Omaha to central Utah. In the valley of Eagle River it consists of a, single layer of brownish-yellow sandstone 30 to 40 feet thick. It slopes up the hillside on the right and forms the crest of a ridge that runs nearly parallel with the railroad for a mile or more. Across the river it forms the northeastern slope of the hill in what geologists call a "dip slope."

The formations so far described are fairly hard, and consequently they form the walls of a rather narrow canyon, but immediately over the Dakota sandstone lies the Mancos shale, which is one of the softest rocks in this region. It is so soft that it readily wears away under the action of the weather and the streams, and consequently it seldom or never forms high or large hills. Where Eagle River crosses the outcrop of the Dakota sandstone and cuts into the shale the valley immediately expands to a width of nearly a mile and contains several ranches. In fact, nearly all the shale on the left side of the river has been removed and the valley takes the form of a rock rimmed basin. The beds of rock on the east side of the basin are steeply upturned, but those on the west side dip toward the middle of the basin at a very low angle, which can hardly be detected but which may be seen in the cliffs of shale almost directly ahead. This little basin or downfold of Cretaceous rocks forms the-extreme southern tip of the great syncline or basin of Cretaceous rocks which carries the valuable coal beds of Routt and Moffat counties, in the northwestern part of the State, and which underlies most of southwestern Wyoming.

Wolcott Area

As the train passes milepost 317 the traveler, by looking back the way he came, may obtain another glimpse of the high peaks of the Holy Cross Range, which, if they are covered with snow, are still conspicuous objects above the horizon. After the traveler passes the axis of the syncline, between mileposts 317 and 318, he can see the gentle rise of the rocks on the west (left) of the railroad in a great cliff of shale, which is nearly ahead but which may be seen on the left from milepost 318. Some bands of white, impure limestone can
be followed by the eye, and these indicate clearly the rise of the beds toward the west, but a still better marker of their rise is the Dakota sandstone, which lies below the surface in the central part of the basin but which rises f rom stream level just below the station at Wolcott and from that place westward forms a battlemented wall along the canyon.

The north side of the valley is marked by a high cliff of the Mancos shale, but the other side is nearly flat and can be cultivated, so that if makes an agreeable break in the line of canyons and narrow valleys through which the traveler has been passing. Until the building of the " Moffat road," in 1906, Wolcott, although but a small village, was one of the principal distributing points for the region to the north as far as the Wyoming line, and a stage was run daily between Wolcott and Steamboat Springs. At that time the region now included in Routt and Moffat counties was noted chiefly as a stock-raising country and thousands of cattle were annually shipped east over the Denver & Rio Grande Railroad from Wolcott and Rifle. Since the completion of the " Moffat road " Steam boat Springs and the region round about receive their supplies directly from Denver, but a stage line is still maintained from Wolcott to State Bridge, 14 miles distant, the nearest point on the Moffat road."

On leaving Wolcott the train plunges into another canyon, which extends for a distance of about 5 miles. The Dakota sandstone forms the cap rock of the walls of this canyon, especially on the north side, but the surface back of the rugged cliffs rises gradually to much greater heights. The sandstone appears above railroad level just below the station at Wolcott, where it consists of a brownish-yellow sandstone, about 80 feet thick. It abounds in impressions of stems and leaves of plants, which show that at the time it was deposited the country was covered with trees, many of them similar to those living to-day in the more humid regions of the United States. At that time there were no Rocky Mountains, and the deposition of this sand, which has since been hardened into sandstone, was followed by a great invasion of salt water, which formed a sea that stretched from Iowa to Utah and entirely across the United States from north to south. In that sea lived animals that produced shells much like the shellfish of the present day, and on the death of the animals the shells dropped to the bottom and there became embedded in fine mud. Today that sea bottom has been elevated thousands of feet above its former position, the sea water has drained away, and the limy muds have been hardened into shale in which the shells are preserved with all their beautiful ornamentation. The traveler can verify this statement for himself by finding well-preserved fossil sea shells in the railroad cut just east of the station at Wolcott.

The station at Wolcott is built on the Dakota sandstone, which in a short distance to the west rises above track level, so that the underlying variegated shale and sandstone (Gunnison formation) and the rocks still lower in the geologic column come into view as the traveler pursues his way down the river bank. As the train rounds the first sharp curve below the station the variegated beds of the Gunnison formation may be seen on the north (right), where they have been exposed by the cutting for the railroad track. About a mile below the village the Dakota lies. about 300 feet above the level of the track and the lightred sandstone of the Triassic makes its appearance at that level, but it is so poorly shown that the traveler may not be able to identify it. A view down the river valley from this point, however, shows that the bright-red sandstone is very conspicuous in the cliffs-it is, in fact, the most prominent rock to be seen. In this part of the canyon the red sandstone is so brilliant that the outcrop looks like a flame or a mass of red-hot iron on the hillside. At Kent siding, just beyond milepost 321, the valley is somewhat wider than it is farther upstream, and the traveler may obtain, on the north, an excellent view of the canyon wall, which is about 175 feet high and is capped by Dakota sandstone and the brownish-red sandstone that marks the top of the Triassic system of rocks.

Although the canyon is in general very narrow there are at some places along the river level lands and small farms. The stream, like all others in this region, is fringed with cottonwood trees and willows, but among these are interspersed dark spruce trees, which give a pleasing contrast. In summer there is a decided difference between the dark-bluish tint of the spruce trees and the soft green of the cottonwoods and the willows, but the color effects are at their best in early autumn, when the leaves of the cottonwoods and the willows are a brilliant yellow.

Owing to the westward rise of the rocks the canyon walls grow higher and higher, but near Ortega siding (mileposts 323-324) the Triassic red sandstone rises above track level and the canyon ends, because as soon as the hard beds rise above drainage level they are undermined by the cutting away of the soft shale of the lower (Maroon) formation. The canyon is in places rugged and picturesque, but generally it will be remembered for its brilliant coloring rather than for the configuration of its rocky walls.

The valley below the canyon resembles the valley cut in the same rocks near Avon, but the hills here are lower than those about Avon and are cut more deeply by the tributary streams. The main valley, however, contains few striking scenic features, but it is interesting for its many fine farms and comfortable residences.

Near milepost 327 the band of bright-red rock on the higher hills across the river is very conspicuous. As shown on the map, it does not extend far to the west, for it loops around and connects with the exposure that was crossed a few miles above Wolcott. Toward the north the Triassic rocks extend for a long distance, but they are not visible from the train. The traveler may be able to trace the Dakota for some distance, but it eventually fades from sight, and then the most prominent rock is a dark basalt that caps the highest hill 6 or 8 miles to the north. This rock is a remnant of what was once probably a continuous sheet of lava, that was poured out on a nearly level surface before the present canyons were cut, when the general surface of the country coincided with the tops of the present highest hills and plateaus. It should not be supposed, however, that the surface at that time was higher above sea level than it is today; indeed, it may have been not nearly so high, for it may have been raised to its present level since the lava was poured out. Other remnants of this sheet of lava may be seen farther down Eagle River.

Eagle Area

The thriving village of Eagle stands at the junction of the valleys of Brush Creek and Eagle River, in the midst of a rich agricultural district, which presents a pleasing contrast to the bare rocks of the canyon walls and to the badlands that the streams have produced in the bluffs bordering the main valley. Although the general altitude of the valley is rather high, good crops of hay, grain, and potatoes are raised, and much live stock finds pasturage on the surrounding uplands. The railroad crosses Eagle River just before reaching Eagle and remains on the south side of that stream as far as its junction with Colorado River.

After leaving Eagle the traveler may obtain another glimpse of the Holy Cross Mountains on the left, up the broad valley of Brush Creek. For some distance below this point the bluffs of the river are so high that they shut out from view the country on the south (left), but farther west the bluffs recede, from the river and grow lower and lower until the upland on the south is clearly visible. This upland now takes on the aspect of a broad, sloping plateau that culminates in the Holy Cross Mountains, which form a most striking feature, especially when they are covered with snow and the intermediate country is still clothed in its summer verdure.

The Holy Cross Mountains are usually regarded as the westernmost range of the Rocky Mountains. The traveler who is pursuing his way along the bottoms of these canyons may not be aware that he has passed out of the Rocky Mountains and has entered a province marked by very different surface features, but if he could obtain a comprehensive view of the country from some high point he would see at once that the great ranges of the Rocky Mountains lie entirely to the east, and that although mountain ranges are visible to the west they are neither extensive nor continuous. The region into which he is now entering is a land of plateaus, some low and some high-nearly as high as the peaks of the Rockies. It is also called a land of canyons, for it includes most of the canyons of the Colorado River system. Country of this type extends westward from the Holy Cross Mountains to the west side of the Wasatch Plateau in the vicinity of Provo, Utah.

Gypsum Area

For about 6 miles below the town of Eagle the, valley of the river continues much the same as it is about the town. The railroad is built on a terrace that stands 60 to 80 feet above the river, and in places this terrace is surmounted by another about 50 feet higher. The bluffs on the north side of the valley become conspicuous because of their barrenness and because they are being rapidly dissected by rivulets produced by every shower. Gypsum Creek, another large stream, enters the main valley from the south at the village of Gypsum. The creek and the town are so named because of the occurrence in abundance of the mineral gypsum in the neighborhood. The village of Gypsum is a supply point for large districts both to the north and to the south. The region near the village is devoted largely to farming, but beyond the farms there is a large area of open range, upon which a great number of cattle are fattened each year.

The red sandstone of the Triassic comes into the tops of the hills below Gypsum, and as it is the hardest rock in the series exposed here it tends to form a canyon that has high and apparently precipitous walls. Near milepost 337 the railroad enters the canyon, which is not so narrow as it at first appears. This canyon is not so picturesque as the canyon in similar beds below Wolcott, for in the canyon below Gypsum the hard red sandstone lies high in the hills and is underlain by soft clay and shale, which wear away rapidly, so that the harder sandstone above breaks down, forming a long, gradual slope back from the stream, whereas in the canyon below Wolcott there are no soft beds exposed below to be eroded and to undermine the harder rocks above, so that the red sandstone cliffs rise almost directly from the water.

As the traveler enters the canyon below Gypsum he may see that the bright-red beds lie in the form of a downfold (syncline) -that is, they are higher at the ends of the canyon than in the middle. This structure may not be apparent to him at first, but at a point between mileposts 338 and 339 he may easily see that the red beds directly opposite the train are lower than the same beds are either to the right or to the left. This lowest point is called the axis of the syncline; it is the line toward which the beds dip from both sides. The layer of rock at the extreme top of the hill on the right is dark brown and not red like the underlying beds, and it does not lie parallel with the other beds but caps the hills without conforming to the dip of the beds beneath. The dark rock is so far away that the traveler can not distinguish its character, but if it were nearer he would see that it is basalt, similar to the sheet of basalt that caps the canyon walls below Wolcott.

In passing down the canyon, before he arrives at the junction of Eagle River and Colorado (Grand) River, the traveler has spread before him one of the finest examples of a recent lava flow that can be found in this country. He can first see this lava flow in the distance on the right soon after he passes milepost 340, in a low, dark hill in the bottom of the valley. The rock of this hill may not at first attract his attention, but on approaching it nearer he can see that it is nearly black and presents a striking contrast to the light-colored rock of the sides of the valley. This rock can be seen at close range at a point about half a mile farther along, where it forms a terrace across the river bottom which suggests that the valley was at one time filled up to a certain level with this black rock. On closer inspection this black rock is seen to be very rough and broken, and those who are familiar with lava flows will at once recognize its character, though others may have difficulty in realizing that this mass of rock was once molten matter that was forced up from the interior of the earth through some vent in the solid crust and that flowed down into this valley much as thick molasses flows in cold weather. This fiery mass could not flow rapidly, for its outer part was continually cooling and being " frozen " into solid rock. The crust thus formed would hold the lava for a time, but it would finally burst and the fiery flood would once more roll along until it was again held up by the cooling of the surface. This drawing off of the liquid lava produced caverns beneath the solid crust, which in time broke and fell in, so that the surface is now very rough. The edge of the flow can be seen from the train as it follows the bank of Eagle River on the opposite side.

The traveler has now seen the lava flow, though he has probably not seen the vent or volcano from which it must have come, but if he scans closely the hills across the valley he will see that some of them are littered with fragments of the same dark rock that composes the flow and that others consist wholly of that rock. The volcano must have been near the top of the first series of hills, but its crater is now obscured by the lava that consolidated in its throat. The vent was small, but it has all the essential features of a true volcano. The ravine down which the fiery flood rolled into the valley, leaving some of the melted rock adhering to its sides as it passed, may be seen from the train.

This eruption seems to have been the last expiring gasp of forces that long before poured out immense floods of molten material in this region. The material erupted at this place was only enough to fill the valley to a depth of 50 or 60 feet but not enough to turn the river from its course. The lava extends down the valley half a mile beyond milepost 341.

As the train rounds the bend, just below the limit of the lava flow, the valley of Colorado River is visible on the north (right), and Eagle River unites with this stream a few hundred yards farther on, but the junction is not near enough to be seen from the train. Colorado River has its source on the east slope of Mount Richthofen, in the northern part of Middle Park, and those who went to the summit of the mountains (Corona) on the "Moffat road" could look down on this west side into some of the head tributaries of this river. After flowing westward across Middle Park the river escapes from that natural basin in the mountains by Gore Canyon, a rugged gorge which it has cut through the Park Range-the same range which the traveler saw on the east (right) at Tennessee Pass. Gore Canyon is cut in granite, but below the Park Range the valley is much like that of Eagle River, consisting of a succession of narrow canyons with stretches of broad valley between. This alternation is repeated many times along the river before it is joined by Eagle River at the siding of Dotsero. At the point of junction there is visible far to the north a high plateau, which is locally called The Flattops or the White River Plateau, from the stream that drains its western slope. It has an altitude of 11,000 to 121000 feet and is noted as the greatest hunting ground of western Colorado. It was here that Theodore Roosevelt made one of his famous hunting trips while he was President of the United States. The preservation of the plateau at this high altitude is largely due to the fact that soon after its even surface was formed it was covered from some vent in this region with lava, which afterward cooled and consolidated into a basalt that has successfully withstood the action of the elements and still preserves its nearly level surface. The lava sheet that caps the high hill on the north side of the canyon below Wolcott was probably once a part of this same flow or flows but has been separated from it by the canyon cut by Colorado River.

Dotsero Area

After passing milepost 342 and a small cut a few hundred yards beyond the railroad track reaches the bank of Colorado River, which it follows to the western border of Colorado. This part of the country is noted for its cattle and horses, and the siding of Dotsero is maintained largely for their shipment. There are no red rocks in the valley of Colorado River just below the mouth of Eagle River, but the rocks there exposed are about as hard as the soft red and green shale and sandstone above. At first the traveler may not be able to identify any of the dull-gray and slate-colored rocks below Eagle River with those he has seen farther upstream, but a comparison of the section and of the order of the formations may show him that these beds are the same as the heavy cliff-making sandstone and shale which he saw just below Minturn. It might be supposed that the same formation should show the same composition and hardness wherever it is exposed, but as these formations consisted originally of sand, clay, and limy materials that were deposited in some body of standing water, either a lake or the sea, it is apparent that the character of the formation at any place must depend largely upon the kind of material there swept into the body of water by the streams, and as the land near by was probably composed of various kinds of rocks, which furnished various kinds of material, it does not seem strange that at one locality a formation. may consist largely of sandstone and at another of shale. Changes from sandstone or shale to limestone are more rare, but such changes are observed in many parts of the country. The soft materials, including some coal beds that are exposed below Eagle River, belong to the Weber formation, which is in the lower part of the upper Carboniferous rocks.

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