Rocky Mountain exploratory drilling reached its peak in 1950. Of 406 wells drilled, 83 were successful and 30 discovered new fields. Successes increased 4 per cent over the previous year to the total of 20.4 per cent. Again Cretaceous sands were the primary objectives and nearly three-fourths of the new producers were in these formations. For the first time geophysical methods led in the discovery of new fields in the region.

Geophysical activity showed a slight decline in crew weeks worked and a noticeable redistribution of working areas toward the newer exploratory regions of the Williston and Denver-Cheyenne basins. Development drilling continued at about the same rate as in 1949.

Rocky Mountain oil production reached the all-time peak with the production of 93 million barrels of oil, due principally to the heavy increase in Wyoming's output which also broke its all-time high.

Highlight of exploration in 1950 was the rapid and successful development of the eastern flank of the Denver-Cheyenne basin in northeastern Colorado and western Nebraska. Thirteen Cretaceous new-field discoveries were made in this basin. This year marks the entrance of western Nebraska as a full-scale oil-producing area. In the Powder River basin of Wyoming additional discoveries were made on the flanks of large known structures, as Cretaceous stratigraphic traps and fault accumulations carried on the exploratory trend of the previous year. In the Big Horn basin of Wyoming, deeper drilling was given impetus by the Permian discovery at Slick Creek.