National Petroleum Reserve Alaska, Alaska

National Petroleum Reserve Alaska is a mostly undeveloped federal area at the top of Alaska, covering 23 million acres (nearly the size of Indiana). Long suspected to be a rich petroleum resource, it was established as the Naval Petroleum Reserve Number 4, in 1923, to be used as a military fuel supply in the event of a national need. Ultimately it was transferred from the Navy to the Interior Department in 1976, and is now administered by the BLM. Although test wells and limited production wells had been drilled by the USGS and the Navy as late as the 1970s, no commercial production had been authorized until 2015, when the BLM issued drilling and right-of-way permits to ConocoPhillips Alaska, for its proposed Greater Mooses Tooth Unit project. The project involved the construction of an 11.8-acre drilling pad, as well as the use of above-ground pipelines to transport oil to the Trans-Alaskan Pipeline. (ConocoPhillips Alaska has had a producing field situated in the reserve since 2001, but it lies atop land owned by Alaska Natives.) The active oil production area of Prudhoe Bay and other North Slope fields are outside the eastern edge of the reserve.