U.S.B.M. Pilot Hole 'X', Horse Draw, Rio Blanco County, Colorado

Pilot Hole 'X' was drilled to test the formations through which the ventilation shaft for the proposed U.S.B.M. demonstration oil shale mine would be drilled ... Correlation of the geologic horizons encountered in this hole with those encountered in nearby drill holes was accomplished by the use of geophysical logs. Data on the geophysical interpretations are provided.