The 93‐square‐mile experimental watershed in Reynolds Creek is aimed toward the solution of water yield, flood flow, and sedimentation problems of the plateau and foothills grazing areas of the northwest. This watershed was selected in 1960 specifically to permit experimental isolation of the several factors affecting the well‐known water balance equation. Basic networks for measurements and compilation of inventories of soils, vegetation, surface geology, and topography have been substantially completed. Detailed studies on small, simple watersheds with identifiable characteristics will provide basic understanding of hydrologic processes, which can be tested on the larger, complex subwatersheds of the Reynolds Creek basin.