and capacity of any reservoir site that could be found on the project at such an elevation that part of the pumping could continue the year round and the size of the units for pumping be decreased. The only such site found is in the northeast corner of T. 14 N., R. 24 E. It would be formed by placing a dam across the mouth of a swale. This reconnaissance proved that no reservoir was obtainable that would not be prohibitive on account of cost. In March, 1905, contour lines were run out to determine the acreage in the Priest Rapids tract under each 100-foot contour up to 400 feet. At this time a plane-table survey of the power canal was made, on the scale of 1,000 feet to the inch, from the head of the rapids to the second power-house site. About 14 miles of topography in all was taken and a profile of the river made from the head of the rapids for the same distance downstream. From the topographic map of the canal line the selection of power-house site No. 1 was made and the characteristics of both sites determined. In June, 1905, three gage boards were placed along the river, one at the head, one at the middle, and one at the foot of the rapids. These are to give the variations in river height, and from their readings the available head will be determined. This concludes all the surveys so far made, and all estimates are based on the information thus obtained.

BIG BEND PROJECT.

The only sources of water supply available for the irrigation of the large area of land lying in the Big Bend of Columbia River are Spokane River and Cœur d'Alene Lake. The enormous expense involved in the diversion of water from either of these sources far exceeds the funds available for this purpose, and for this reason no field work on this project has been done during the past year.

PALOUSE PROJECT.

About 100,000 acres of land in the vicinity of Pasco, lying between Columbia and Snake rivers, may be irrigated from Palouse River. Active investigation was begun May 1, 1904, under the direct charge of C. Andersen. Storage reservoirs were located and studied, one on the main river below Hooper; one on Rock Creek, a tributary of the Palouse; one on Hangman Creek, a tributary of the Spokane; and one in Washtucna Coulee, below the point of diversion on the main river. Plane-table surveys were made of canal locations and of the irrigable lands. Borings were made and test pits dug at the various proposed dam sites and along the lines of canal, and careful estimates were prepared. A board of consulting engineers, consisting of A. P. Davis, A. J. Wiley, D. C. Henny, and T. A. Noble, considered the project in April, 1905, and recommended that for the present no further work be done on it for the following reasons:

(1) The most important feature of the project, the Washtucna reservoir, with a capacity of 200,000 acre-feet, is of doubtful feasibility, owing to the character of the rock underlying the gravel bottom. (2) The porous character of the ground in which the canals were to be excavated would necessitate concrete lining for long distances, to prevent excessive seepage. (3) The sandy character of the soil of the irrigable lands, in connection with climatic conditions and unavoidable seepage in main canals and laterals, would necessitate provision for an unusually large supply. (4) The cost per acre of irrigated land might be estimated at $63. (5) The entire estimated cost of $6,300,000 exceeds greatly the amount of money available for construction in the State of Washington, and partial construction, with gradual extension of the irrigated area, is impracticable.

CHELAN PROJECT.

The attractive possibilities of developing cheap water power at Chelan, for electric transmission to pumping plants along Columbia River, have led to a preliminary investigation and to the withdrawal from entry of unpatented lands lying along Lake Chelan and Chelan River, between the Washington Forest Reserve and Columbia River. A reconnaissance survey is in progress, and complete investigation may be desirable at an early date.

OPERATIONS IN WYOMING.

By H. N. SAVAGE.

SHOSHONE PROJECT.a

Reports concerning the earlier work on the Shoshone project may be found in the Second Annual Report of the Reclamation Service, pages 507-510, and in the Third Annual Report, second edition, pages 626-631.

TOPOGRAPHIC SURVEYS.

In May, 1905, a party was organized for the purpose of completing the topographic work begun in September, 1904, on the south side of Shoshone River. This work covers an area of about 24,000 acres of irrigable land, which had been segregated by the State of Wyoming under the provisions of the Carey act, and which during the present year has been relinquished to the United States by the State land board. The topographic survey of this land was completed in September, 1905. There is now a complete topographic map, on a scale of 1,000 feet to the inch, with contour interval of 10 feet, of the entire area of irrigable land under the project as now planned. This map is of great value in making preliminary locations of all canal lines, headgates, and other structures for the distributing system, and for all purposes where a thorough study of the topography is necessary.

CORBETT TUNNEL.

The final location of the Corbett tunnel has been decided (Pl. LVIII), and borings have been made along the tunnel line for the purpose of determining the probable character of the material that would be encountered in driving the tunnel. The borings indicate that the material is shale and sandstone, and that concrete lining will be necessary. The tunnel will head in Shoshone River opposite Corbett station, on the Cody branch of the Chicago, Burlington and Quincy Railroad, the water being diverted into the tunnel by a weir 17 feet high and about 600 feet long. The line of tunnel is parallel to the general direction of the bluffs along the river, and at several points is close enough to them for adits to be excavated from the faces of the bluffs to the tunnel. This will give a means of dividing the tunnel into several short sections for construction purposes. The lower portal of the tunnel will be in a ravine about 17,000 feet from the upper portal in Shoshone River, this being approximately the total length of the tunnel. The area of the cross section of the tunnel will be 100 square feet, and its capacity 1,000 second-feet. At a point in the ravine above referred to, about 1,000 feet below the lower portal of the tunnel, will be constructed an earth embankment 40 feet in height, 150 feet in length on top, upstream slope 3 to 1, riprapped 10 feet below the surface of the water, downstream slope 2 to 1, top width 10 feet. This embankment will form a settling basin (Pl. LIX) in which practically all silt passing through the tunnel will be deposited, so that the water will pass into the main canal comparatively free from silt. A spillway will be constructed across a ridge between the settling basin and Shoshone River; through this spillway all surplus water that may enter the settling basin from drainage tributary to it will be discharged, and it will also serve as a regulator for the water entering the canal, the crest of the spillway being at the same elevation as the surface of the water in the canal. A sluicing tunnel 4 by 5 feet in cross section and about 250 feet long will be constructed through a ridge on the opposite

a From report by Jeremiah Ahern.

side of the embankment from the spillway for the purpose of sluicing out the silt that will accumulate in the basin (Pl. LX).

On September 6, 1905, bids for the construction of the Corbett tunnel were opened at Billings. Five bids were received, the lowest ($594,325) being that of Charles Spear, of Billings, Mont., to whom the contract was awarded September 16, 1905. The following is a schedule of the bids received:

Bids received for the construction of Corbett tunnel, Shoshone project, Wyoming.

The main low-line canal will head at the settling basin and extend nearly to Frannie station, on the Cody branch of the Chicago, Burlington and Quincy Railroad, a distance of 42 miles. It will have a capacity of 1,000 second-feet for the first 9 miles, decreasing in size as the distributing canals leave it. The final location of this canal has been made. The preliminary location of all the distributing canals covering the land in the vicinity of Garland and the final location of several of them have been made. This distributing system will cover the land known as the Garland flat, an area of about 50,000 acres. The portion of the main canal extending from Garland to Frannie, with its distributing systemnot yet finally located-will cover approximately 30,000 acres in the vicinity of Frannie. H. Doc. 86, 59-1-24