St. Mary Land & Exploration Co., Denver, (NYSE: SM) has acquired assets in South Texas from Tulsa, Okla.-based Rockford Energy Partners II LLC for $151 million. The assets include 98% average working interest (77% average net revenue interest) in 259 wells on 56,799 net acres in the Olmos formation that is adjacent to the company's Catarina field assets in Webb and Dimmit counties. Production is 9.2 million cubic feet of gas equivalent per day (97% gas). Proved reserves are 94.8 billion cubic feet equivalent (37.8 billion proved developed) and proved, probable and possible reserves are 160.8 billion cubic feet equivalent.