1961 was the most active year in the history of Alaska's petroleum development. Twenty-five exploratory wells were spudded, compared with 13 in 1960. Development wells spudded increased from 16 in 1960 to 27 in 1961. Two new gas fields were discovered on the Kenai Peninsula, Cook Inlet area. Production in both wells was from the Tertiary Kenai Formation. Geophysical activity increased 83% from 47 3/4 crew-months in 1960 to 87 1/2 crew-months in 1961. Surface geology remained at approximately the 1960 level. Nearly half of all surface mapping was conducted by 6 major oil companies in the Brooks Range-Arctic Slope area. Total area under Federal oil and gas leases decreased from 33,287,120 acres to 26,807,695 acres, and area under Alaska oil and gas leases increased from 117,203 acres to 501,065 acres during the period from Dec. 31, 1960, to Dec. 31, 1961. Active federal development contracts increased from 7 to 13 over the same period. Alaska received $22,415,940.16 from competitive-bid sales of oil and gas leases, located predominantly in the Cook Inlet area. 1962 is expected to show a decrease in surface geologic mapping and development drilling. Exploratory drilling and geophysical exploration are expected to approximate the 1961 rates.