This report summarizes estimated volumes of oil and gas in undiscovered conventional and continuous-type accumulations that occur on onshore Federal Lands. The basis of these estimates is the U.S. Geological Survey's 1995 National Assessment of oil and gas resources (Gautier and others, 1996). Onshore Federal Lands account for about 29 percent of US land area but only 5.1 percent of 1995 US oil production and 8.8 percent of 1995 US gas production. Estimates are as of January 1994. The Minerals Management Service has released a parallel study for Federal offshore areas (1996).