Exploratory and development drilling targeted for Middle Silurian Niagaran reefs again dominated Michigan's oil and gas industry activity for the twelfth straight year. Drilling was concentrated predominantly in the northern counties along the reef trend. Reef exploration also continued in the region of Ingham, Eaton, and Calhoun counties and in parts of southeastern Michigan. Several significant deeper pool tests were commenced in older fields in the central basin. In the same area, deeper development drilling in older fields continued at a high pace. Exploration resulted in 62 new discoveries. Of the new discoveries credited to 1980, 46 were new Niagaran reef reservoirs, 28 of which were located along various parts of the northern reef trend. The discovery of two new re fs in Oceana County has expanded the area of interest in the search for these Middle Silurian reservoirs. Exploration and development footage figures, derived from Geological Survey Division (Michigan Department of Natural Resources) records, amounted to 1,375,993 ft exploratory and 1,468,038 ft development, compared with 1,146,515 ft exploratory and 1,150,710 ft development drilled in 1980. An additional 212,101 ft is credited to facility and miscellaneous wells drilled in 1980. Oil and gas production peaked in 1980. Preliminary figures show that 33,900,000 bbl of oil (including condensate) and 158,302 mmcf of gas were produced in 1980. Niagaran reef reservoirs located along the northern reef trend accounted for about 73% of the oil and 83% of the gas produced in 1980.