The State of Wyoming has a long history of oil and gas production, and its producing basins remain some of the most active in terms of current drilling activity and production. Oil wells were first drilled in Wyoming beginning in 1884 and the largest oil producing regions are the Powder River Basin, the Green River Basin, the Big Horn Basin, the Overthrust Belt, and the Wind River Basin.
In June 2012, we completed the NiMin Acquisition to acquire crude oil properties in the Big Horn Basin in central Wyoming. The NiMin Assets are 100% oil and produced approximately 497 Bbl/d in the fourth quarter of 2012. Estimated proved reserves for the NiMin Assets as of December 31, 2012 were 5.4 MMBoe.
Our other Wyoming properties consist primarily of crude oil properties in the Powder River Basin in eastern Wyoming, principally natural gas properties in the Evanston and Green River Basins in southwestern Wyoming and principally oil fields in the Wind River and Big Horn Basins in central Wyoming including Gebo, North Sunshine, Black Mountain, Hidden Dome, Sheldon Dome, Rolff Lake in Fremont County, Lost Dome in Natrona County (outside the Wind River and Big Horn Basin), West Oregon Basin and Half Moon. In total, we have interests in 964 productive wells in Wyoming.
For the year ended December 31, 2012, our average production from our Wyoming fields was approximately 7.2 MBoe/d, including average daily production from acquisition date to December 31, 2012 for properties acquired during 2012. Our Wyoming estimated proved reserves as of December 31, 2012 totaled 39.4 MMBoe. As of December 31, 2012, approximately 53% of our Wyoming total estimated proved reserves were oil. Our capital spending in Wyoming for the year ended December 31, 2012 was approximately $32 million.