Additional laws focused on protecting the area's rustic and undeveloped character. In 1948, the Thye-Blatnik Bill authorized the government to purchase the few remaining privately owned homes and resorts within the area. In 1949, President Harry Truman signed Executive Order 10092 which prohibited aircraft from flying over the area below 4,000 feet. The area was officially named the Boundary Waters Canoe Area in 1958. The Wilderness Act of 1964 organized it as a unit of the National Wilderness Preservation System. The 1978 Boundary Waters Canoe Area Wilderness Act established the Boundary Waters regulations much as they are today, with limitations on motorboats and snowmobiles, a permit-based quota system for recreational access, and restrictions on logging and mining within the area. That same year the Forest Service began referring to it as "BWCAW" to recognize its wilderness character.