The Exxon Valdez oil spill occurred in Prince William Sound, Alaska, on March 24, 1989, when Exxon Valdez, an oil tanker bound for Long Beach, California, struck Prince William Sound's Bligh Reef at 12:04 am local time and spilled  of crude oil over the next few days. It is considered to be one of the most devastating human-caused environmental disasters. The Valdez spill was the largest in US waters until the 2010 Deepwater Horizon oil spill, in terms of volume released. However, Prince William Sound's remote location, accessible only by helicopter, plane, or boat, made government and industry response efforts difficult and severely taxed existing plans for response. The region is a habitat for salmon, sea otters, seals and seabirds. The oil, originally extracted at the Prudhoe Bay oil field, eventually covered of coastline, and of ocean.