Indiana's oil production for 1961 totaled an estimated 11,460,000 bbls., a decrease of approximately 594,000 bbls., or 5% from the 1960 production. The total number of wells drilled decreased from 1072 in 1960 to 788 in 1961, a drop of nearly 27%. Of the 788 total wells drilled, 246 were wildcat wells and 542 were field-development wells. Thirty of the wildcat wells were successful, 12 being completed as new pools, 10 as extensions to pools, and 8 as new pays in productive areas. Twenty-four successful wildcat wells were completed in rocks of the Mississippian System, 2 in the Devonian, and 4 in the Ordovician. Pennsylvanian and Mississippian formations of southwestern Indiana continued to be the principal objectives of exploratory drilling. Successes in Chester reservoirs in southeastern Pike County were significant. These successes indicate that the area of shallow Chester reservoirs throughout eastern Pike County, southern Daviess County, and Dubois County is worthy of further exploration. Exploration for underground gas storage sites continued during 1961. Stratigraphic units tested include Devonian, Silurian, Trenton, and Knox strata.