Moses Coulee till, up to thick in places. This glacial till, made up of clay, silt, sand, gravel, cobblestones, and erratic boulders, covers most of the upper coulee. Today Moses Coulee supports an excellent example of a shrub-steppe ecoregion. Vegetation includes sagebrush, rabbitbrush, greasewood, hopsage, bitterbrush, bunchgrass, buckwheat and other vegetation once common to most of the Columbia Plateau. The Nature Conservancy has established the Moses Coulee Preserve, which is a contiguous, intact shrub-steppe habitat. It is located south of Jameson Lake near the head of Moses Coulee. It provide habitat for a rich variety of birds (lazuli bunting, common goldeneye, sage
Grand Coulee Dam to oversee the dam project, and Reclamation was selected to oversee construction. On July 16, 1933, a crowd of 3,000 watched the driving of the first stake at the low dam site, and excavation soon began. Core drilling commenced that September while the Bureau of Reclamation accelerated its studies and designs for the dam. It would still help control floods and provide for irrigation and hydroelectricity, though at a reduced capacity. Most importantly, it would not raise its reservoir high enough to irrigate the plateau around the Grand Coulee. However, the dam's design provided for future raising and upgrading. Before