Between 1965 and 1967, the US Government exploded nuclear weapons on Amchitka Island in the Aleutian island chain in southwest Alaska. Amchitka Island is the traditional homeland of Aleut Alaska Natives, who lived on Amchitka until the arrival of Russian settlers in the 1760s. Russian settlers forced many Aleut to move from Amchitka to the nearby island of Adak. Others were killed by diseases brought by the Russian settlers. In 1913, the Aleutian island chain was designated a wildlife reservation by President William Taft. Unfortunately, the executive order made the islands vulnerable to government appropriation for military and economic purposes.
In 1965, the US conducted the first nuclear explosion on Amchitka. An 80-kiloton nuclear blast was set off underground. Scientists used this blast for research purposes. It was analyzed by seismologists to help determine whether other countries were conducting underground nuclear testing.
A second blast was set off in 1969, 4,000 feet below the surface of Amchitka. This exercise was used to understand how larger underground explosions “might damage the island, trigger seismic activity, or generate tsunamis. Workers drilled a 4,000-foot hole.”
The most notorious explosion was conducted in 1971, “Project Cannikin.” At 5-megatons, this blast was 250 times more powerful than the bomb dropped on Hiroshima. It was detonated almost a mile below Amchitka’s surface. The detonation caused the ground surface on Amchitka to rise, then fall 20 feet. A crater a mile wide and 40 feet deep on Amchitka’s surface serves as an ominous reminder of the massive explosion. The shock from the explosion measured 7.0 on the Richter scale, the same as the 2010 earthquake that devastated Haiti. A social movement against Project Cannikin by a group of environmentalists from British Columbia inspired the formation of the group Greenpeace.
Radioactivity continues to leak into the ocean, groundwater, and air in and around Amchitka. These blasts created underground, rubble-filled cavities which trapped high concentrations of nuclear contamination underneath Amchitka. Groundwater moving through these cavities can pick up radioactivity, carrying it to the ocean. Researchers are still working to figure out how these blasts affected and are continuing to affect Alaska. In 1997, Anchorage biologist Pam Miller, working on a research project for Greenpeace, found radioactive particles, including americium-241 and plutonium, in freshwater samples from the edge of the Bering Sea. The US Department of Energy claims that its environmental testing proves otherwise.
Footage of the 1971 Project Cannikin nuclear explosion.
 Kieran Mulvaney, "A Brief History of Amchitka and The Bomb," Greenpeace, August 25, 2007, https://www.greenpeace.org/usa/a-brief-history-of-amchitka-and-the-bomb/.
 Ned Rozell, “The Unknown Legacy of Alaska's Atomic Tests,” University of Alaska Fairbanks, January 18, 2001, https://www.gi.alaska.edu/alaska-science-forum/unknown-legacy-alaskas-atomic-tests