A test-drilling program was conducted by the U.S. Geological Survey in the upper Sevier River drainage basin (fig. 1) in the summer of 1962. The program was part of a ground-water investigation made in cooperation with the Utah State Engineer. The drilling was financed cooperatively through the State Engineer by the U.S. Geological Survey, Garfield, Piute, Sevier, Sanpete, and Millard Counties, and various water users within those counties. Drilling began in May and continued through September 1962, and 21 test holes were drilled.