The National Landscape Conservation System (also known as the National Conservation Lands) is a 30-million-acre (120,000 km2) collection of lands in 872 federally recognized areas considered to be the crown jewels of the American West. These lands represent 10% of the 258 million acres (1,040,000 km2) managed by the Bureau of Land Management (BLM). The BLM is the largest federal public land manager and is responsible for over 40% of all the federal public land in the nation.