Geological Survey Bulletin 707 Guidebook of the Western United States: Part E. The Denver & Rio Grande Western Route

Soon after leaving the Union Station at Denver, on the main line of the Denver & Rio Grande Western Railroad, the train crosses Cherry Creek near the place where Gen. Larimer built the first house, in 1858. As this creek heads out on the plains it is intermittent in its flow; in dry seasons little or no water runs in it at the surface, but when "cloudbursts" occur on its upper course a tremendous volume of water comes down, engulfing everything in its way. Such a catastrophe occurred in May, 1864, when great damage was done. Recently the channel of the creek, where it passes through the city, has been cemented, so as to prevent the loose sandy soil from washing away, and a boulevard bordered by trees has been constructed along it, giving its banks here the appearance of a park.

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⁸The figures given for population throughout this book are those of the United States census for 1920; for places that were not incorporated the figures given represent the population of the election precinct, township, or other similar unit; such figures are marked with an asterisk (*)

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The Denver & Rio Grande Western Railroad traverses the manufacturing part of Denver, and at Burnham, 2 miles out from the city, it passes the shops of the railroad system. About half a mile beyond the shops is the interesting though unpretentious laboratory building erected by the National Radium Institute for experimental work in cooperation with the United States Bureau of Mines to devise a cheaper method of extracting radium salts from the ores found in Colorado. This work has been accomplished, and the plant has now passed into the hands of a private company to continue the work of extracting radium.⁹

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⁹The National Radium Institute was organized by Dr. Howard A. Kelly, of Baltimore, and Dr. James Douglas, of New York, not for private gain but for the purpose primarily of studying the curative properties of radium and secondarily to show that radium can be produced here at a much lower cost than abroad. When the institute was organized radium was selling for as much as $120,000 a gram. As Congress had failed to reserve for public use the land containing radium ores or to foster the development of the radium industry in this country, the National Radium Institute undertook to provide the ways and means for experimental work to determine whether or not the ores could be reduced at a smaller cost than abroad and thus to place radium within the reach of hospitals throughout the country.

The Bureau of Mines had already reached the conclusion that such a reduction in cost was possible, and an agreement was reached by which the bureau was to cooperate with the institute for the benefit of the people. The Institute leased claims in Paradox Valley, in southwestern Colorado, and the Bureau of Mines mined the ore and shipped it to Denver for treatment by the bureau. The work has been successful, and the bureau has patented a process by which radium was produced at a cost of about $40,000 per gram, or one-third its selling price. This patent may be used free of charge by anyone who cares to use it for the benefit of the American people.

All this valuable work has been done in the unpretentious plant at Denver. For further information the reader is referred to Bureau of Mines Bulletin 104.

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A short distance farther along South Platte River may be seen on the west (right), and the railroad runs up its valley for a distance of about 15 miles. The valley is well irrigated and contains many fine farms and country places. Loretto Academy stands out clear and distinct as one of the landmarks of the upland on the farther side of the river. Fort Logan, just beyond, is a regimental Army post established about 25 years ago.

Littleton is the county seat of Arapahoe (a-rap'a-hoe) County, so named from a tribe of Indians that formerly inhabited this part of the country. It stands in the midst of a rich agricultural district and has become popular as the suburban home of many of Denver's business men. Near Littleton are the W. F. Kendrick pheasantries, which are said to be the largest game preserve in the world. Here all kinds of wild fowl are raised, and golden pheasants may be seen wandering by the roadside like chickens on an ordinary farm.

A short distance beyond Littleton the traveler may obtain a charming view on the right, across the broad, well-tilled valley of the South Platte, studded with clumps of cottonwood trees, to the Front Range, towering in the distance. Wolhurst, a fine country place built by the late United States Senator Edward Wolcott, is farther along on the right, just beyond milepost 13. After the death of Senator Wolcott the place was purchased by the noted mining man the late Thomas F. Walsh. It is now occupied as a country home by one of Denver's richest citizens.

At the small station of Acequia the railroad crosses the High Line Canal, one of those great irrigating ditches that are characteristic of the semiarid regions, which takes water from the South Platte and carries it far to the northeast, irrigating at least 100,000 acres of land that would otherwise be arid and unprofitable. The railroad follows the valley of South Platte River to a point a little beyond milepost 15, where it leaves the main valley and turns to the south (left) up Plum Creek. This creek also flows in a broad, flat valley, and the traveler, unless he observes closely, may not realize that the railroad has turned from the main valley into that of a tributary.

Near milepost 15 the entrance to South Platte Canyon may be seen in the mountain front, on the right. Here, in 1820, the exploring expedition of Maj. Long first came to the mountains, although it had traveled from the north for many miles. in front of and nearly parallel with them. The men were eager to climb the mountains, explore their wonderful peaks and valleys, and see the country that lay beyond, but a few days of hard climbing up the rocky slopes satisfied them that they could not reach the summit of the range in a short time and that mountain climbing was not so easy as it appeared from a distance; so they were content to proceed southward along nearly the route that is now followed by the Denver & Rio Grande Western Railroad. The entrance to the canyon may be seen from the train, but, owing to its many bends, the canyon does not appear to be an open cut through the mountain front.

In many places at the foot of the mountains the steeply dipping sandstone forms sharp hogbacks, which may be seen from the moving train, and, as the sandstone is mostly red, the traveler will soon learn to associate red sandstone and hogbacks with the foothills of the mountain front. These beds are very prominent near the mouth of Plum Creek and may be seen to good advantage from milepost 17, about 1-1/2 miles up the creek.

The scenery of the lower part of the valley of Plum Creek is smooth and uninteresting. The surface is a rolling upland, which can not be irrigated from the South Platte because it lies too high above that river, and it consequently appears rather barren to those who are accustomed to a more humid climate. The only railroad station in this part of the valley is Louviers, which is merely a shipping point for the DuPont Powder Co., whose plant for the manufacture of high explosives is on the west (right) of the track.

Above Louviers Plum Creek swings eastward, and it is bordered on its east side by bluffs and mesas of white sandstone.¹⁰ Although but a short distance from the upturned rocks along the mountain front, these sandstones lie practically horizontal, a fact which indicates that they are near the middle of the great downfold of the rocks east of the Front Range. Figure 6 represents the edges of the upturned rock beds as they would appear if they had been cut by a giant knife at right angles to the trend of the mountain range.

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¹⁰All the rock seen near the railroad track from Denver to a point beyond Palmer Lake is composed of fragments derived from the decomposition of the granite and gneiss of the mountains. This material, which consists mostly of quartz and feldspar, is known to geologists as arkose. The formation is called the Dawson arkose, and it is of the same geologic age as the formations about Denver that have been called the Denver and Arapahoe formations. Richardson, in the Castle Rock folio (No. 198) of the Geologic Atlas of the United States, describes the rock as follows:

"The Dawson arkose, derived from the Pikes Peak granite and associated rocks, was laid down under various continental conditions, chiefly as wash and fluviatile [stream] deposits accompanied by local ponding. During the accumulation of the arkose this region may be conceived of as a piedmont [foot of the mountain] area having a moist and temperate climate, an area in which the vegetation was characterized by the presence of many fig trees, palms, magnolias, poplars, willows, oaks, maples, etc., and which was occupied by Triceratops (huge three-horned dinosaurs), crocodiles, turtles, and other reptiles and by primitive mammals"

In other words, the material derived from the mountains was carried out on a nearly flat surface and deposited by the streams in much the same way as the streams of to-day are carrying the waste of the mountain rocks and spreading it over the low parts of the plains.

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The Atchison, Topeka & Santa Fe Railway, which has been on the east (left) side of the train since it left Denver, passes over the Denver & Rio Grande Western Railroad at the town of Sedalia. The upland on the east is here nearer the track than it is farther north, and it stands out as a plateau with a steep or even vertical front. Some of these steep slopes are merely projecting points of the highland, but others are parts of hills that have been isolated from it by the cutting of the streams. Such isolated remnants of a once extensive plateau are very conspicuous on the west (right) of the road. A hill of this kind in the East would not be called by any special name, but in the West, and especially in the Southwest, a flat-topped hill is almost universally called by the Spanish name mesa, meaning table. Near Sedalia are the forks of Plum Creek, one of which comes from the south and the other from the east. The one that comes from the south offers the more direct course for the railroad, but the one that comes from the east is the longer and has the better grade, so it was selected, even though its course is more roundabout.

FIGURE 6.—Section at mouth of Platte Canyon.

The most prominent of the mesas is Castle Bock, which may be seen far ahead on the right soon after the train passes Sedalia. When first seen it is so far away that it seems to be only a small hill, but as the train proceeds it becomes more conspicuous, until at a siding called Plateau it appears on the right as a very prominent conical hill surmounted by a thick, square block of rock. This mesa was first mentioned in the report of the exploration of Maj. Long, in 1820, and on account of its resemblance to an old ruin was called Castle Rock.

As the train approaches milepost 32 the traveler may see that the railroad is built around the foot of Castle Rock mesa, which is about 300 feet high and has a cap rock 60 or 70 feet thick. This mesa is shown in Plate XI, A, and in figure 7. The lower part of the mesa is composed of soft, friable beds of the Dawson arkose, but the cap rock is a coarse conglomerate of pebbles and boulders of crystalline rocks of all sorts that have been washed out from the mountains and of a volcanic rock (rhyolite) which caps also some of the adjacent mesas. These materials were washed out of the mountains by streams of water and dropped as sheets of gravel and boulders upon the surface of the land. The county seat of Douglas County, named in honor of Stephen A. Douglas, stands at the base of the mesa and bears the name Castle Rock. It was formerly noted for its stone quarries, the remains of which still disfigure the mesas, but the increasing use of cement in construction work has so depressed the market for ordinary building stone that the quarrying industry has nearly disappeared. Samples of the stone may be seen in the Douglas County High School building, on the right as the train enters the town, and in the station building of the Denver & Rio Grande Western Railroad.¹¹ This stone was once molten lava that was poured out as a thin sheet over the surface of the country, after the Dawson arkose was deposited but before the coarse materials of the Castle Rock conglomerate were spread over the plain.

FIGURE 7.—Castle Rock from the north.

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¹¹According to Richardson the rhyolite is said to have been first quarried about 1876, and it is reported that up to 1914 about 30,000 carloads had been marketed. The stone has been extensively used for building in Denver, Colorado Springs, and Pueblo, where it has given general satisfaction. The quarries, to which railroad spurs have been constructed, are near the town of Castle Rock. The stone is readily accessible, is easily worked, is of pleasing gray to pinkish color, stands the weather well, and is sufficiently strong for ordinary purposes, although the more porous varieties are not adapted for use where great strength is desired. In recent years the production of this stone has fallen off because of the competition of other building materials.

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In following the valley of Plum Creek from Sedalia to Castle Rock the railroad swings far to the east of a direct line from Denver to Colorado Springs. After passing Castle Rock it turns back toward the mountains, its course being nearly due south to Palmer Lake, and the prolongation of this course would lead almost directly to Pikes Peak. This majestic mountain is too nearly straight ahead to be visible at many points, but here and there as the train swings around some of the numerous curves it may be seen in the distance towering far above the surrounding summits.

To those accustomed to the more humid regions of the East, with their dense cover of vegetation, the open spaces of the West, the red rocks, and the strong yellow light of the plains are here the most striking features. The wonderful color effects of this region are beautifully expressed by Helen Hunt Jackson, Colorado's most gifted author:

Colorado is a symphony in yellow and red. And as soon as I had said the words, the colors and shapes in which I knew them seemed instantly to be arranged in my thoughts; places miles apart began to knit themselves together into a concerted and related succession; spots and tints I had only vaguely recognized became distinct and significant, each in its order and force; and more and more as I looked from the plains to the mountains and from the mountains to the plains, and stood in the great places crowded with gay and fantastic rocks, all the time bearing in mind this phrase, it grew to seem true and complete and inevitable.

Mesas composed of white arkosic sandstone are seen on both sides of the railroad, but one on the right, 2 or 3 miles beyond Castle Rock, is the most prominent. This mesa, which is known as Dawson Butte, furnished the geologic name of the formation—the Dawson arkose. Just beyond milepost 37 there appears, seemingly from behind this mesa but in reality far beyond it, a jagged mass of red granite, which towers 1,000 feet above the general level of the Front Range plateau. This rugged mountain, known as Devils Head, is utilized by the Forest Service as a lookout station for the detection of forest fires. (See Pl. XV, B, p. 31.) On its lonely summit is stationed, throughout the summer, an observer whose duty it is to scan continually the surrounding mountain region for forest fires, and if he discovers one to notify at once, by telephone, the superintendent of the Pike National Forest, so that all the rangers can be called together to fight the fire. A more extended description of what the Government is attempting to do for the conservation of the forests is given below by Smith Riley, former district forester.¹²

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¹²Colorado lies in the zone of slight precipitation and hence of irrigation, and the supply of water for this purpose comes from the mountains, where the moisture falls as snow during the winter. The presence of trees controls and prolongs this stream flow by preventing erosion and retarding the melting of snow in the spring and early summer.

The forest on the mountains is composed of many different species of trees, and the range in elevation of these species is controlled largely by moisture and temperature. The piñon or nut pine and cedar trees are found near the plains or in the zone of smallest precipitation. Above this zone, as the precipitation increases, is that of the western yellow pine (Pl. XIV, C) and Douglas fir, with blue spruce on small tracts. Above the zone of yellow pine is the zone of lodgepole pine (Pl. XXXVI, B, p. 76) and above this, extending to timber line, is the zone in which Engelmann spruce (Pl. XIII, B) and alpine fir are intermixed. Throughout the zones of yellow and lodgepole pine and even in that of Engelmann spruce, quaking aspen occurs in abundance. This tree, which presents a wonderful richness of autumnal coloring, has a marked tendency to seed quickly areas that have been severely burned. As it grows rapidly it soon forms a cover and acts as a "nurse tree," under which conifers that require more moisture start to grow and ultimately take possession of the area and kill out the aspen. Several varieties of cottonwood are found in the moist stream bottoms, in the zones of the yellow pine and piñon, and out on the plains.

One of the white or five-needle pines grows on exposed slopes high in the zone of the yellow pine. This tree, which is called limber pine, has little commercial value but is very picturesque because of its gray-green foliage and whitish bark. Its pale-yellow cones are larger than those of any of the other pines in this region, and many of the trees are distorted into curious and picturesque shapes by the severe climatic conditions under which they grow.

In the zone of the lodgepole pine and on the more exposed ridges there is another five-needle pine called bristlecone or sugar pine. This tree derives its names from the recurred prickles or thorns at the extremity of the cone scales, and from the exudations of resin on the surface of the needles or leaves, which when dry look very much like particles of sugar.

To maintain a cover for an even stream flow and protect the supply of timber all the more extensive drainage basins of the United States have been included in national forests. There are seventeen such forests in Colorado, comprising over 13,000,000 acres of mountainous country.

A forest, which is based upon natural subdivisions and administrative lines, contains from 400,000 to 1,600,000 acres and is in charge of a forest supervisor and a corps of assistants. Every forest is further divided into ranger districts, each containing from 50,000 to 200,000 acres. Such districts are in charge of rangers, who police them and look after all business pertaining to the national forest.

The Pike National Forest includes the mountains west of Denver and Colorado Springs. It includes most of the drainage basins from which Denver, Colorado Springs, and many smaller towns, having altogether a population of about 350,000, derive their domestic water supply. In addition to this supply its streams furnish water for irrigating 400,000 acres of rich agricultural land at the foot of the mountains.

The region now included in this forest furnished an immense amount of timber during the early development of local industries, about 500,000,000 feet b. m. having been cut prior to its establishment as a national forest. In the mountains farther west, particularly at Howard, travelers may notice rows of domelike structures looking like large beehives of the old-fashioned wicker type. (See Pl. XIV, B.) These are charcoal kilns. They represent all that is left of the charcoal industry, which, before coke was available, furnished fuel for smelters, greatly to the detriment of the timber stands of the regions.

In Gilpin County considerable areas of forest land were practically denuded, for trees of all sizes and even stumps were removed and utilized. This cutting was followed, from time to time, by fires which fed upon the "slash" left on the cut-over areas and killed the remaining trees. The bare hills then permitted a rapid run-off of water after heavy rains, which caused considerable destructive erosion. Similar conditions mark other parts of the Pike National Forest, but erosion has not cut so deeply into the slopes, and owing to generally favorable conditions, many areas have naturally become reforested.

In the early days all ranch buildings were constructed of logs, and even furniture was made by the settlers. The trees also furnished the entire supply of fuel. In many localities they serve the same purposes to-day—the ranchers and new settlers put up their own buildings of logs obtained from the national forest under free-use permits, or established ranchers can purchase at a low price, equal to the cost of administering the sale.

From 1875 to 1895 most of the railroads of the mountain region were built, and practically all construction was done with local timber. Most of the cutting was done by small operators, with sawmills of 6,000 to 10,000 feet b. m. daily capacity, who would locate or purchase a small tract of timber land and then cut not only that but the timber on adjoining Government land. The operators of that day paid little or no stumpage for their timber and cut only that which was the most easily obtained or which was best suited to their purpose.

Since 1905, when the forests came under the jurisdiction of the Forest Service, the Government's timber has been sold to private purchasers at fair rates of stumpage, and cutting has been restricted to trees whose removal would benefit the remaining stand. The stumpage price charged in each sale is the difference between the market price of the product and the estimated cost of production plus a liberal allowance for profit to the operator.

The amount of timber cut in the Pike National Forest for the year ending June 30, 1921, was 3,420,000 feet b. m., for which $4,900 was paid the Government for stumpage. In addition, about 1,000,000 feet b. m., mainly of dead material, was granted free to settlers and miners for their own use.

The area of the Pike National Forest is 1,256,112 acres, of which 162,956 acres is patented or privately owned, and 108,000 acres is above timber line. The present stand of timber in the forest is estimated to be 1,100,000,000 feet b. m., of which 620,000,000 feet b. m. is considered to be in commercial stands and 480,000,000 feet b. m. in protection stands.

The following list gives the species in the order of their abundance in the present merchantable stands, the names in parentheses being those often used by local timbermen: Engelmann spruce (white spruce), yellow pine (immature timber is called blackjack), Douglas fir (red spruce), lodgepole pine, white pine, limber pine (white pine or piñon), bristlecone pine (sugar pine or piñon), alpine fir (white fir), white fir (balsam or black balsam), Colorado blue spruce (water spruce), and aspen (quaking asp). Of these, Douglas fir is the most valuable for railroad ties and lumber for other purposes, and yellow pine second.

When an application for a timber sale is received by the Forest Service it is first necessary to determine whether the timber applied for should be sold. Where dead timber is available and will answer the purpose its use is encouraged. The object of cutting green timber is to improve the stand by the removal of the mature and defective trees, which are growing very slowly, and to thin crowded groups of trees, leaving a stand of younger thrifty saplings and poles with plenty of growing space and permitting young trees to come in wherever there is not already a sufficient stand. In order to improve the stand and keep it in the best of condition for future growth it is necessary to base the time and method of cutting on the needs of the forest rather than on the desire of the operators. In the slow-growing stands of this forest it will generally be from 30 to 50 years or more after the first cutting before the area should be cut over again.

PLATE XII. A (top). RESULT OF A RECENT FOREST FIRE. Scarred and blackened tree trunks and half-burned logs mark the path of a recent fire through the national forest. Photograph by the U. S. Forest Service. B (bottom). RESULT OF AN OLD FOREST FIRE. An old "burn" in a national forest. Its pathway is marked by the white skeletons of the dead trees, which are ready to fall in a hopeless tangle when struck by a hard wind. Photograph by the U. S. Forest Service.

PLATE XIII. A (left). MARKING MERCHANTABLE TIMBER. Marking trees in midwinter for a national forest timber sale. Photograph by the U. S. Forest Service. B (right). ENGLEMANN SPRUCE. A typical stand of Englemann spruce, which grows only at high altitudes. Photograph by the U. S. Forest Service.

In a Forest Service timber sale each green tree to be cut is designated by blazing and stamping it with a "U. S." stamp. This marking is necessary in order that the trees which are to form the basis of the future stand will not be destroyed. (See Pl. XIII, A.) After the marked trees are cut and skidded or hauled to a central point, the material is scaled or measured by a forest ranger and there sawed into lumber by a small mill. Contracts for the sale of green timber provide for the disposal of the brush and debris resulting from the cutting. Where there is a serious menace of fire the purchaser is required to pile the brush and burn it when there is no danger of the fire spreading. Where the danger from fire is not so great, or where some protection of the soil is needed to induce reproduction, the purchaser is required to trim the tops and scatter the brush so that it will lie close to the ground, where it will absorb moisture and decay rapidly. The proper disposal of brush is the most necessary measure for the protection of a cut-over forest from fire.

In the early days of settlement in this country the forest suffered considerably from fires. (See Pl. XII, A and B.) The present fire-fighting methods and organization were unheard of. In 1869 a fire started by hunters on Pikes Peak is said to have burned intermittently for eight months and to have covered many thousands of acres, though there were several times during this period when a small crew of men could have extinguished it. Similar fires covered about 250,000 acres in the Pike National Forest, and of this area 60,000 acres is not restocking but must be reforested.

While visiting Colorado Springs the traveler will notice burned-over areas on the slopes of Pikes Peak. Several cities and towns procure their water supply from the slopes of this mountain, so it is of great importance that the forest growth be extended and maintained. An agreement has been entered into between the Forest Service and the cities of Colorado Springs, Manitou, and Cascade that the service shall reforest these slopes as rapidly as the funds available will permit. Already about $100,000 has been expended in this work, and complete plans have been formulated for its continuation until tree growth has been established upon the entire area suited to the purpose. In making the trip to Pikes Peak over the automobile highway the traveler passes through several of these plantations.

PLATE XIV. A (top). A FOREST NURSERY. The Monument nursery of the U. S. Forest Service, in which young trees are grown from the seed. This nursery contains 1,729,000 seedlings and 810,000 transplants, which later will be used for reforesting some of the burned-over areas. Photograph by the U. S. Forest Service. B (middle). OLD CHARCOAL KILNS. Into such kilns as these much of the forest of the Rocky Mountains has disappeared. The charcoal which it made was used before coke became available for smelting ores. Photograph by the U. S. Forest Service. C (bottom). YELLOW PINE. Typical stand of yellow pine in the Pike National Forest. Photograph by the U. S. Forest Service.

In order to accomplish this planting a nursery has been established just west of the town of Monument (Pl. XIV, A). At the present time over 1,500,000 tree seedlings and 600,000 transplanted trees are growing in this nursery. These trees will be planted in the mountains when they are two to three years old at a distance of 6 to 8 feet apart. During 1920 the area thus reforested comprised 738 acres and the planting required 570,000 trees.

Forest fires still cause great destruction in the national forest. (See Pls. XII, A, B, and XV, A.) The possibility of fires in the Pike National Forest is great, because eight railroads traverse it, 5,000 people live in it, and 250,000 tourists seek recreation within its borders. On the summit of Devils Head Mountain the Forest Service has established a fire-lookout station (Pl. XV, B), at which an officer is detailed to watch for fires during spring, summer, and autumn. This officer is in direct communication by telephone with the supervisor's office in Denver and with the rangers whose districts he overlooks. As soon as a fire is discovered he gives its location promptly and accurately so that the rangers can start with men, tools, and supplies to fight it.

PLATE XV. A (top). A PLACE FOR ARTIFICIAL REFORESTATION. A tract on the mountain back of Palmer Lake burned so severely that artificial reforestation is necessary. The mountain top here is almost a perfect plain (a peneplain). Pikes Peak, in the distance, rises nearly a mile above its surface. Photograph by the U. S. Forest Service. B (bottom). FIRE-LOOKOUT STATION. On Devils Head Mountain, in the Pike National Forest. The observer stationed here is on the lookout for all forest fires occurring in an area of 600,000 acres. In case of fire he notifies by telephone the superintendent at Denver and the local forest rangers, who at once endeavor to put out the fire before it spreads and destroys valuable timber. Photograph by the U. S. Forest Service.

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Above Dawson Butte the railroad continues up the valley of East Plum Creek, winding around a projecting spur of the plateau on the east to the village of Larkspur, from which a stage line runs to the resorts in Perry Park, 4 miles to the west. This is a natural parklike area at the foot of the mountains, made picturesque by natural monuments of tilted and highly colored sandstone. Although less known than the Garden of the Gods, near Manitou, it is similar in general appearance and by many is regarded as fully equal to it in natural beauty. In these castellated rocks those who have a vivid imagination can see mystic monuments and towers, battlemented walls, minarets and steeples, and the remains of vast cities that still reflect in the massiveness of their ruins some of their former grandeur. To the geologist these buttes and plateaus are also the ruins of a former age, but instead of being carved by man and representing cities that have passed away they were carved by water and wind from an older and higher land surface that carried its own particular types of plants and animals and that had a climate which may have been very different from the climate of to-day. Compared with these remnants of this old land surface the most ancient ruined cities are as the works of yesterday.

Larkspur Butte on the east and Raspberry Butte on the west are small remnants of this old surface. Beyond them the upland has been cut away, leaving a rather broad valley in which stands the hamlet of Greenland. After passing this village the train turns more toward the southwest and pursues a direct course toward the low gap which separates the headwaters of East Plum Creek on the north from those of Monument Creek on the south. This gap is at the foot of the mountains and is marked by Palmer Lake, the highest point on the line between Denver and Pueblo. This lake and its relation to the mountain front are well shown in Plate XVI, B. The lake and town were named for Gen. Palmer, the organizer, first president, and inspiring genius of the Denver & Rio Grande. Railroad. A more extended account of Gen. Palmer and his work will be found on pages 54-60. The town of Palmer Lake is composed largely of cottages for summer guests who come here for health and recreation. The railroad station is 1,957 feet higher than Denver and 1,248 feet higher than Colorado Springs. Glen Park, an assembly ground modeled after the famous Chautauqua of New York, is about a mile from the station. The mountain front west of the lake rises abruptly, as shown in Plate XVI, B, to a height of 1,800 feet above the level of the lake. The summer cottages nestle in the ravines at the base of the mountain and afford the inhabitants the advantages and attractions of both the plains and the mountains.

The mountain front rises abruptly from the plain without foot hills of any kind. The reason for the absence of foothills is that the rocks of the plains, when they were bent by the upthrust of the mountains, could not stand the strain to which they were subjected, and in many places they broke and the lower crystalline rocks of the mountains were forced up into direct contact with the broken edges of the soft, flat-lying rocks of the plains, forming what is called a fault. The positions of the rocks and their relations are shown in figure 8. The effect of this fault has been much the same as that of the small faults shown in Plate LXXXVII, A and B (p. 216).

FIGURE 8.—Sketch section through Palmer Lake, showing fault. The granite on the west has moved up (see Pl. LXXXVII, p. 216) with reference to the rocks of the plains.

From Palmer Lake to Colorado Springs the railroad extends down the valley of Monument Creek, so named from the pinnacles and columns of white sandstone (Dawson arkose) that are left by the irregular weathering of prominent outcrops. The first conspicuous example is on the east (left) of the road, where a mass of the sandstone has weathered into a form resembling an elephant. (See Pl. XVI, A.) On account of this resemblance it is generally known as "The Elephant." The valley immediately south of Palmer Lake is narrow, but in a short distance it swings to the east and at the village of Monument is broad, irrigated, and well farmed.

PLATE XVI. A (top). "ELEPHANT ROCK." Just after passing Palmer Lake the guide on the train will call attention to the "Elephant" one of the grotesque remnants of the Dawson arkose which has weathered into a form resembling an elephant. Photograph by G. B. Richardson. B (bottom). PALMER LAKE. On a hot day in summer one of the most refreshing sights between Denver and Colorado Springs is the little sheet of water known as Palmer Lake. It lies on the divide between the Arkansas and the Platte and also at the foot of the Front Range, which shows on the right. Photograph furnished by the Denver & Rio Grande Western Railroad.