Three hundred forty-five exploratory wells were drilled in the Rocky Mountain region in 1949, of which fifty-six were commercially successful. This is a gain in drilling over the previous peak year of 1948 when 277 exploratory tests were drilled. Successes, however, declined 10.1 per cent below the 1948 figures. Cretaceous objectives provided the greatest number of producers followed by the Permo-Pennsylvanian formations. Of nineteen new fields discovered, credit goes first to geologic methods alone, followed by a combination of geologic and geophysical methods. New discoveries at Sussex and Glenrock in the Powder River basin of Wyoming were of significance as they emphasize the trend toward exploration of the flanks and noses of large known structures in search of fault raps. Stratigraphic accumulations have proved added incentives in this type of exploration. A new Tertiary discovery at Roosevelt in the Uinta basin of Utah has pointed to new objectives which open large areas for exploration.

Development drilling showed a slight decline over the peak of 1948; however, Weston County, Wyoming fields more than doubled their 1948 rate of activity. Geophysical exploration showed a substantial increase in the number of crew weeks of gravity and seismic work done with some regional shift of emphasis. The Rocky Mountain region was subjected to heavy leasing campaigns in the Williston basin of North Dakota, the northeastern Colorado part of the Denver-Cheyenne basin and in the Uinta basin of Utah. Production for the region was down due to decline of black-oil demand. In 1949 Utah became a full-fledged oil-producing state.