History of the Bureau of Land Management (BLM) The Bureau of Land Management (BLM), an agency within the U.S. Department of the Interior, manages the remainder of the public domain -- a once vast expanse of land held in ownership by the United States Government for the American people. The original 1.8 billion-acre public domain stretched from the Appalachian Mountains to the Pacific Ocean -- so much land that Western historian Frederick Jackson Turner called it "the richest free gift that was ever spread out before civilized man." Of these 1 ....