Discovery of Red Wash field was the result of a long and persistent effort on the part of many geologists and geophysicists. Surface expression of an anticlinal nose was first detected on aerial photographs and modifications were made by field mapping. Detailed stratigraphic studies along the outcrop at Raven Ridge indicated that potential stratigraphic traps existed in northern source sandstones of the Eocene Green River Formation. Gravity studies in the area, although not conclusive, furnished supporting evidence that the structural nose existed at depth. A detailed seismic program confirmed the existence of the Red Wash nose and furnished data to map its structural configuration at several horizons within the lower Green River Formation. Information now available from ver 350 wells in the area indicates that prediscovery geologic concepts were remarkably accurate. The Douglas Creek and Garden Gulch Members of the Green River Formation form a lacustrine delta at Red Wash and yield hydrocarbons from a complex network of discrete sandstones. The individual sandstone bodies form separate stratigraphic traps. Cumulative production at the end of 1967 was more than 57 million bbl of oil, and ultimate recovery is expected to exceed 150 million bbl.