Drilling in Wyoming in 1963 totaled 905 wells, of which 377 were exploratory tests and 528 were development wells. The percentage of success in new-field wildcats was 6.3, the poorest showing since 1956, and in all exploratory drilling, 13.2. The most active area of the state was the Powder River Basin which produced 12 of Wyoming's 20 new-field discoveries, followed by the Big Horn and Green River Basins. Other parts of Wyoming followed the same general level of activity as in previous years. Idaho had only one well in 1963, an unsuccessful new-field wildcat.