Exploratory drilling in the Four Corners-Intermountain area increased sharply in 1981, with 335 wells drilled. Drilling activity was up in all states. A total of 129 successful wells was completed, yielding a success rate of 38.5%, up from 28% in 1980. Total exploratory footage drilled was up nearly 79.5% from 1980, with 1,980,462 ft drilled in all exploratory categories.

Development drilling increased 28.2% from 1980 with 1,414 holes drilled, most of which were in the San Juan basin, as in previous years. The region's most significant discovery was in the Overthrust belt of northern Utah, where the confirmation test of the Anschutz Ranch East field was completed by Anschutz. The 8-20u Anschutz Ranch East (Sec. 20, T4N, R8E) flowed 7,268 mcf of gas and 1,488 bbl of condensate from Nugget (13,050 to 13,574 ft).

In southeastern Utah, the Superior 27-32 Sentinel Peak (Sec. 27, T41S, R26E) flowed 552 BOPD and 423 MCFGD from the Middle Pennsylvanian Ismay (Paradox). In Nevada, Northwest Exploration opened the Bacon Flat field with the discovery well pumping 222 BOPD and 619 BWPD from Paleozoic rocks at 5,316 to 5,354 ft. Exploratory drilling remains high in the region with the Overthrust belt and Cordilleran hinge-line area attracting most of the attention. However, increased activity in Utah's Uinta and Paradox basins accounts for the bulk of the state's drilling.