what is the size of an acre of land
Acre The acre is a unit of land area used in the imperial and US customary systems. It is traditionally defined as the area of one chain by one furlong (66 by 660 feet), which is exactly equal to ​1⁄640 of a square mile, or 43,560 square feet, and approximately 4,047 m2, or about 40% of a hectare.
Federal lands The federal government owns about 640 million acres of land in the United States, about 28% of the total land area of 2.27 billion acres.[3][4] The majority of federal lands (610.1 million acres in 2015) are administered by the Bureau of Land Management (BLM), U.S. Fish and Wildlife Service (FWS), National Park Service (NPS), or U.S. Forest Service (FS). BLM, FWS, and NPS are part of the U.S. Department of the Interior, while the Forest Service is part of the U.S. Department of Agriculture. An additional 11.4 million acres of land (about 2% of all federal land) is owned by the U.S. Department of Defense (DOD).[4] The majority of federal lands are located in Alaska and the Western states.[4]