Aniakchak National Monument is in southwestern Alaska . It lies in the Aleutian Range in the middle of the Alaska Peninsula. The monument is most famous for its giant volcanic caldera (craterlike depression). A national preserve adjoins the monument.
The Aniakchak Caldera is in the Aleutian Range. It was formed about 3,500 years ago by the collapse of a 7,000-foot (2,130-meter) volcanic mountain. The crater is about 6 miles (10 kilometers) across and ranges from about 2,000 to 4,400 feet (610 to 1,340 meters) deep. Surprise Lake—a lake that formed within the caldera—is the headwaters of the Aniakchak River. The river empties into Aniakchak Bay of the North Pacific Ocean, about 27 miles (43 kilometers) to the southeast. The area is home to brown bears, caribou, sockeye salmon, and a number of bird species.
The monument and its adjacent preserve are among the most remote sites in the National Park System . No roads connect it to other parts of Alaska, and frequent storms batter the area. Visitors who do reach the Aniakchak area may enjoy such activities as hiking, photography, and whitewater rafting. The National Park Service designated the Aniakchak Crater (later renamed the Aniakchak Caldera) a national natural landmark in 1970. President Jimmy Carter established the Aniakchak National Monument by proclamation in 1978. The monument was enlarged and designated a national monument and preserve in 1980.
