when irrigated are very fertile and yield luxuriantly a fine quality of fruit, berries, etc., considerable quantities of which are shipped out annually.

The river banks slope back to a height of many hundreds of feet, and the bunch grass found thereon offers a sparse but fairly good grazing for sheep and cattle. On high plateaus, some miles back from the river, are the richly productive wheat fields of eastern Washington and Oregon. Much of the wheat, now amounting to many millions of bushels annually, raised in the Camas and Clearwater basins, Palouse and Big Bend countries, and the Wallawalla and Wallowa regions now passes down the Snake and Columbia River valleys by rail. For a further description of the Snake River, including description of the rapids and bars and the work done in past years, attention is respectfully invited to Annual Reports of Chief of Engineers for 1877, page 1037; for 1889, page 2583, and for 1891, page 3218.

Previous improvement. The Upper Columbia and Snake rivers having formed one of the most important highways of travel in the region in early days before the railroads were completed, Congress, as early as 1872, made appropriations for the improvement of the Columbia, and in 1876 the Snake was added to the plan of improvement. From that time up to the present a total of $288,500 has been appropriated for both rivers, of which, as near as can be learned from the records, $117,850.57 have been applied to the Snake River from Lewiston down to its mouth, mainly below Riparia. The original project was to secure a depth of 4 feet at low water from the mouth up to Lewiston. The greater part of this improvement was made below Riparia, as the dangers and difficulties met with by steamboats were greatest there. The method of improvement consisted mainly in blasting out obstructing bowlders, removing dangerous ledges, scraping sand and gravel bars, and the construction of dikes to concentrate the river flow in selected channels. This work on the Lower Snake below Riparia was stopped in 1888, as the steamboats had abandoned that section upon completion of the railways paralleling it, and the expenditures since then being small have all been devoted to improving the portion in actual use between Riparia and Lewiston.

In 1892 $20,000 and in 1894 $25,000 were, as before referred to, appropriated for the improvement of the Snake from Huntington bridge down to the Seven Devils mining district. Considerable work was done in freeing the river from obstructions in this locality. Considerable plant was collected, including drill scows, tools, etc., and the work of removing ledge rock and bowlders was carried on for several seasons. Only one steamer, the Norma, was ever built for navigating this section of river, and she made but one trip, and then the owners abandoned the idea of running. In 1896 all the Government plant in this portion of the river was sold and the river improvement abandoned.

Before the improvement of the Lower Snake was commenced there were many shoal places where there was not over 2 feet depth at low water. At many rapids the channel, besides being shoal, was rocky and thickly studded with obstructing bowlders, and was very crooked and intricate. The currents were very swift at places, and the early attempts at navigation were accordingly attended with frequent delays, much risk, and occasional loss. The effect of the improvement has

been to remove ledge rocks from many places below Riparia, partially straightening the channel, and freeing the river of many obstructing points. Many bowlders have been blasted, and sand and gravel bars scraped, both above and below Riparia. At several places considerable benefit has been obtained by the construction of dikes, closing undesirable channels and directing the river flow into selected places to occasion scour and increase the depths.

Above Riparia the present condition meets fairly well the present demands of navigation at all stages except at and near extreme low water. Extreme low water is seldom reached and only occasionally are boats prevented from using the river for this reason, and then for only short periods. Much delay is experienced near low-water stages, however, by having to "line" the boats over bars and by having to run with only partial loads.

Previous examinations and surveys.-An examination of the Upper Columbia and Snake rivers was made in 1866 by Lieut. (now Lieut. Col.) W. H. Heuer, Corps of Engineers, and an estimate of cost of improvement made (see Annual Report, Chief of Engineers, 1866, Part IV, p. 330), amounting to $166,686, with $6,000 annually for dredging. In 1877 a further examination, with estimate of cost of improvement, amounting to $132,000, was made by Maj. (now Brig. Gen.) John M. Wilson, Corps of Engineers. No continuous survey of the Columbia and Snake rivers has ever been made up to the present day. The plans of improvement proposed in these projects were for the benefit of the special places found most troublesome by steamboats, and only special, limited surveys of the localities to be improved were made.

In 1897 a survey from Riparia to the mouth was made under direction of Capt. Harry Taylor, Corps of Engineers, and a project and estimate of cost submitted under date of January 27, 1898 (House Doc. No. 411, Fifty-fifth Congress, second session). The project of improvement as stated in this report was for securing at low water a least navigable depth of 5 feet everywhere from Riparia down to the mouth, a distance of 66 miles. The cost was estimated at $165,000, with $3,000 every two years for maintenance.

Present survey.-The present survey was commenced July 28, 1900, and the field work was completed September 24, 1900. The party, numbering 15, was under charge of Mr. Frank Gilham and was composed of a transit party and a level party, with the necessary boatmen, cook, and laborers. The party, using four bateaux, commenced at Lewiston and drifted downstream from time to time with the current when it was necessary to change camp sites. A line of levels, checked by a duplicate set of readings, was carried throughout the entire distance, the zero being the level of mean low water at the sea, assuming as correct the corresponding elevation of low water at Lewiston (709.6) as observed by the Oregon Railroad and Navigation Company. Low-water level was obtained from the zero of the gauge at Lewiston on the Oregon Railroad and Navigation Company's warehouse and from that of the gauge on the central pier of the drawspan of the Riparia Railway bridge. These gauges were read daily at noon during the survey, and were found to indicate fairly well the corresponding stages of water at the two places. These gauges were put in place by the railway companies and have been read for many years by them.

The zeros give the best information available of the level of extreme low water. A traverse line carefully checked was also run over the entire distance as a basis for locating the river's direction, widths, and depths. Current observations were observed with surface floats at all important rapids. Bench marks were left every few miles for future reference. Bank contours 20 feet apart were observed throughout the distance. The total cost of the field work was $2,563, or $34.87 per mile. The office work of plotting, etc., cost $730, making the total cost of the completed survey $3,293, or $44.80 per mile.

A list of the most important rapids, with their location, depth, and slope, is given below.

1

Maps of the plan and profile of the river surveyed, showing the more important shoals on a larger scale wherever improvement is proposed accompany this report.

Commerce. The Snake River drains a vast territory but the commerce that is now affected by its navigability is not extensive. It is limited mainly to the fruit raised along the "bottoms" adjacent to the river and to the wheat, sheep, and cattle that are raised on the plateaus back of the river, and which can be profitably taken to some point where a boat landing can be reached. As all the products of this region beyond that for a local supply must under present conditions be transshipped to rail at either Lewiston or Riparia this means of transportation does not afford the usual competition found in many waterways. This piece of river is therefore practically only a feeder to the Oregon Railroad and Navigation Company's line at Riparia and to the Northern Pacific Railroad at Lewiston. Until an open river is secured in the Columbia between The Dalles and Celilo these general conditions will not be much changed.

The commerce of the Snake River between Riparia and Lewiston for the calendar year 1899 was as follows:

Present condition and improvement proposed. The description of the shoals, rapids, and other obstructed places between Riparia and Lewiston, where trouble in navigation is experienced at the present time, is as follows:

List of rapids, shoals, and prominent points in Snake River from Lewiston, Idaho, to Riparia, Wash.

List of rapids, shoals, and prominent points in Snake River from Lewiston, Idaho, to

Riparia, Wash.-Continued.

Length of river surveyed, 73.5 miles.

NOTE.-Elevations refer to mean low tide at Astoria, Oreg., as given by the Oregon Railroad and Navigation Company's levels.

Water surface refers to extreme low water.

The steamer landing at Lewiston, Idaho, is the commencement point of the survey.