Utah's oil industry managed to survive the slowdown. Developers continued to drill in Washington County's Virgin oil field and completed a total of sixty wells before 1944. Standard Oil of California sank two test holes in Emery County, and the Utah-Southern Oil Company remained active in Grand County, even drilling one well to a depth of 6,715 feet. William E. Nevills, who began to work in the Mexican Hat oil field in the mid-1920s, enlarged his operations by adding three wells to his string of small producing wells.
Toward the end of World War II oil men began to accelerate Utah's petroleum operations once again. This time they succeeded to the extent that from 1945 through 1947 they finished the groundwork necessary to propel the state into a period of commercial oil production. The focal point of these activities was the Uinta Basin. Here a number of large companies such as Standard Oil of California, Pure, Continental, Gulf, Carter, and Union began to explore more seriously than at any time previously. Despite the presence of these major firms, however, the Equity Oil Company, a Utah-based enterprise under the leadership of J.L. Dougan, was the first to find commercial amounts of oil in the Uinta Basin. Dougan was drilling in Ashley Valley on 18 September 1948 when his company tapped a pool of oil that produced 300 barrels a day. Within the next seven years, major oil companies would open Uinta Basin fields, including Roosevelt (1949), Red Wash (1951), Walker Hollow (1953), and Bluebell (1955). These fields became part of two giant oil-producing complexes--Greater Altamont/Bluebell and Greater Red Wash--which ultimately included White River (1961), Cedar Rim (1969), and Altamont (1970).