Marvin “Mr. Wildcatter” Davis has passed away. He was 79. Between 1976 and 1980, his Davis Oil Co., operated 1,169 wells and had almost 500 employees in the Rockies, Midcontinent, West Texas and Gulf Coast. Among discoveries credited to Davis were the 8.5-million-barrel Wallace Field and a handful of additional million-barrelplus Minnelusa discoveries in the Powder River Basin,Wyoming. In the same area, he discovered the 6.4-million-barrel Collums Field, which produces from the Muddy formation. Davis also is credited with the discovery of the massive Jonah Field in southwestern Wyoming, but the focussed fracture treatments hadn’t yet been devised that led to the present-day oil rush in field. He sold most of his production, some 930 wells, to Home Petroleum of Canada in 1981, and continued to operated 356 wells and participated in 89 more. In 1985, he sold most of his remaining properties to Apache Corp., shortly before the oil-price collapse. Davis’ oil-patch legacy lives on: son Gregg Davis’ Houston-based Davis Petroleum Corp. has discovered 215 billion cubic feet of gas and 20 million barrels of oil since its formation in 1998.