lakes at least strongly alkaline. These mountains rise to altitudes of from 3,000 to 4,000 feet above the plains, thus giving rise to large creeks, while the Laramie hills on the eastern side of the plains are relatively but low ridges, rising about 1,500 feet above the bottom lands, and the water from them flows toward the east. The Laramie plains are about 30 miles in width, and 80 miles in length from north to south, and have an average elevation of about 7,000 feet, the town of Laramie being at an altitude of 7,159 feet, according to the railroad levels. In many respects these plains, though larger, resemble the parks within the Rocky mountains. The plain with its ridges and surrounding bench lands is well covered with grass, affording excellent grazing, but owing to the climate there is little agriculture carried on, the chief industry being stock raising. The Little Laramie river rises at about the center of Medicine Bow range, flowing easterly out upon the Laramie plains at a point west of the town of Laramie. This, as above stated, is the only stream which crosses the plains and flows into the Big Laramie. On May 28, 1891, as gauged by the state engineer, the Little Laramie at May's ranch was discharging at the rate of 562 second-feet and on June 7, 1892, at the same place, 618 second-feet. North of this is Seven Mile creek, which empties into James lake. On June 6, 1891, this was flowing at the rate of 40 second-feet, but by August 28 it was nearly or quite dry. About 3 miles further north is Four Mile creek, which on June 9, 1891, was discharging 25 second-feet. Continuing along the base of the mountains for about 8 miles Dutton creek is reached, this stream losing its water in Cooper lake. On June 12, 1891, the discharge was nearly 22 secondfeet, but by the latter part of August this as well as the two creeks above named had become dry. A number of ditches have been taken out of these streams, most of these being from 1 to 6 miles in length. The largest canals are those taken from Laramie river, heading at or below the canyon and continuing along the river toward the town of Laramie, one of these being over 25 miles in length. The waters of all the small streams are being utilized during the summer, and it is probable that some of the floods of spring will be saved in order to increase the acreage which can be watered during the dry season. A gauging of the amount of water in Laramie river at the town of that name was made on October 5, 1892, at which time there was found only 26 second-feet. This represents mainly the excess or seepage water from the canals covering land in the vicinity. Twenty days later the flow had increased to about 63 second-feet as shown by a measurement made by the state engineer. After passing through or around the Laramie hills the river flows easterly out upon the Great Plains, receiving about 18 miles above its mouth Chugwater creek, which flows in from the south through a broad, fertile valley. This latter creek flows northerly along the eastern front of Laramie hills, being formed by the union of small creeks which drain 1 First biennial report of the state engineer to the governor of Wyoming, 1891 and 1892. Cheyenne, Wyo., 1892. Appendix, pp. xviii, xx. this elevated land. Irrigation is carried on along the stream, the water supply being completely utilized, at least during the dry season. In the fertile valley of the Laramie are some of the finest irrigated lands of the state, producing large crops each year. LOWER NORTH PLATTE. Under this heading may be included that part of the river from the mouth of the Sweetwater down to the junction of the South Platte, comparatively little water being used from the main stream, as it is dif ficult to divert it. There is, however, a practically unlimited amount of arable land along the river, which, except for grazing, is worthless without irrigation. The side streams, which come in mainly from the south, are completely utilized, and more land would be brought under cultivation along the course of each if water could be had. Below the Laramie river the principal tributaries are Rawhide creek and Horse creek, both of which discharge small quantities of water, except during floods. Horse creek rises in the Laramie hills, south of Chugwater, the various streams which go to make it up flowing out easterly upon the plains. On the highlands in this vicinity farming without irrigation has been attempted with some success, but no dependence can be placed upon the crops coming to maturity every year. At about the place where the North Platte crosses into Nebraska, and at various points below this, are the headworks of large irrigating canals, some of them in operation, others in various stages of construction. These cover lands on both sides of the river, the greater number of irrigation works being, however, on the south side. In addition surveys have been made for great systems, which, if carried out, will involve the expenditure of millions of dollars. The object in view in these large schemes is to mount the bluffs bordering the bottom lands along the river and thus carry out water upon the plains. These bluffs rise abruptly to heights of 300 feet and over, so that if the project is practicable the canal lines must be very long and expensive. The soil, however, on the plains is doubtless better than that in the valley, being in places less sandy and without an excess of alkaline salts. The valley or bottom lands along the river are being brought under cultivation by irrigation, there being probably a dozen canals already in use. In this part of the Platte drainage basin, however, corn, wheat, and other cereals are usually successfully raised without the application of water. The large amount of water available in the North Platte renders possible the successful operation of extensive systems of irrigation which can be made to cover many thousand acres of fertile bottom land even if the bluffs can not be surmounted. Measurements of the discharge of the river have been made at various points by the state engineer of Wyoming and also by topographers of the U. S. Geological 13 GEOL., PT. III -6 Survey. These have been mainly at Douglas, in Converse county, Wyoming, 70 miles or more above the mouth of Laramie river, also at Fairbanks, Laramie county, about 15 miles above the mouth of Laramie river, and at points in Nebraska from near the state line down to the town of North Platte, at the junction of this river with the South Platte. The following table gives the results of these measurements: These gaugings show that during the latter part of the year the discharge may fall below 500 second-feet, but even with this minimum quantity canals of considerable size can be successfully operated, espe cially if they take water from points along the stream at distances of from 10 to 20 miles from each other. The channel of the river and the adjacent low lands are underlain by pervious sands and gravels containing large volumes of water, and even if one irrigating system takes all of the available water at a given point it is probable that at a distance of 10 miles or more below there will be found flowing a stream of considerable size due to the return of the ground water to the surface The gaugings of this river made by Mr. A. M. Van Auken, mentioned in the preceding report,' doubtless give an exaggerated idea of the low water discharge, and in the light of later official measurements are considered to be misleading. The observations of river height made by him serve, however, to illustrate the relative fluctuations of the river and are therefore given in the accompanying diagram, Fig. 57. SOUTH PLATTE, ABOVE DENVER. The South Platte heads behind the Front range of the Rocky mountains, its upper waters coming from the South Park, which in many respects resembles the region from which come the higher tributaries of the North Platte. The Park range, rising to heights of 13,000 feet and upward, on the west and the Colorado Front range on the east receive a large amount of snow during the winter, which, melting, feeds numerous small streams flowing into the park. The altitude of the valley lands ranges from 8,000 to 10,000 feet, and, as a consequence, only a few of the hardier cereals can be raised. Various kinds of grass, however, grow luxuriantly, especially if water is applied during the Twelfth annual report of U. S. Geol. Survey, pt. 2, Irrigation, pp. 239, 240. dry season. Along each of the small streams, wherever ditches can be successfully located at small expense, irrigation is being carried on and large crops of hay are obtained. The water supply of the South park is relatively large and is freely used upon the hay lands. In a few instances the number of ditches Fig. 57.-Diagram of daily fluctuations of North Platte river, Wyoming, 1887 to 1890. has been so greatly increased that there is scarcity during the dry season, and it is possible that attempts will be made to obviate this by the construction of reservoirs. In view of the great and increasing deficiency of water farther down the stream it seems imperative to utilize all possible methods of saving water in these elevated regions The tributaries of the South Platte in the park flow in a general southeasterly direction, then turn toward the north and pass out in deep canyons through the Front range. A few measurements of these streams were made in 1876 by topographers of the Hayden survey. These show that on July 3 the Middle fork of the South Platte, at a point about 6 miles below Fairplay, discharged 388 second-feet, and at Hartzell's ranch, above the mouth of the Little Platte, on June 29, the discharge was 367 second-feet. Further down, below the mouth of Twin creek, the discharge, on June 23, was 1,015 second-feet, and at the foot of the canyon, on September 8, was 1,400 second-feet. A continuous record of the height of the water flowing in the river was begun by the state engineer of Colorado' on July 12, 1887, at a station near Deansbury in the canyon of the river, about 26 miles above Denver, and where the drainage area is 2,600 square miles. The results of the Fig. 58.-Diagram of daily discharge of South Platte river near Deansbury, Colo., 1887 to 1890. computations of daily discharge are shown in the tables, p. 93, and are graphically given in Fig. 58. Beginning at and below the canyon and extending down toward Denver are several canals which in size rank among the first in the United States. The most extensive of these is that of the Northern Colorado Irrigating Company, commonly known as the English High. line. This extends northeasterly from the river, covering land south and east of the city, and having a total length of 85 miles. Other canals of less size and length carry out water from the river on the U. S. Geol. and Geog. Survey Terr., Hayden, 1876, rept. of Henry Gannett, p. 324. Fourth Bien. Rept. state engineer of Colorado for 1887 and 1888, Denver, Colo., 1889, p. 63; also Fifth Bien. Rept. of same for 1891, p. 19. |