Exploratory drilling during 1979 in the McCallum coal field, Jackson County, Colorado

Rotary drilling of two drill holes in the McCallum coal field, Jackson County, Colorado, was completed by the United States Geological Survey (USGS) in July 1979. The holes are within the area of the short-term lease application. C-27931 held by Wyoming Fuels of Lakewood, Colorado.

Drill-hole GNW1 is located in T. 3 N., R. 78 W., sec. 10, SIANE14, in the Gould NW quadrangle, and drill-hole JMM2 is located in T. 8 N., R. 78 W., sec. 10, SW¹/₂NE¹/₄, in the Johnny Moore Mountain quadrangle (fig. 1). The area is part of the McCallum Known Recoverable Coal Resource Area (KRCRA).

The purpose of the drilling was to gather additional data concerning depth, thickness, and extent of the Sudduth coal bed in order to calculate a reserve base for the area of the lease application. USGS personnel chose the drill-hole sites, conducted the geophysical logging, and recorded the descriptions of cuttings at 5-foot intervals.