<Tr> <Th> Area </Th> <Td> 11,000 sq mi (28,000 km) </Td> </Tr> <Tr> <Th> Shoreline impacted </Th> <Td> 1,300 mi (2,100 km) </Td> </Tr> <P> The Exxon Valdez oil spill occurred in Prince William Sound, Alaska, March 24, 1989, when Exxon Valdez, an oil tanker owned by Exxon Shipping Company, bound for Long Beach, California, struck Prince William Sound's Bligh Reef, 1.5 miles west of Tatitlek, Alaska at 12: 04 am local time and spilled 10.8 million US gallons (260,000 bbl) (or a mass of 35,000 metric tonnes) 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 is the second largest in US waters, after the 2010 Deepwater Horizon oil spill, in terms of volume released . Prince William Sound's remote location, accessible only by helicopter, plane, or boat, made government and industry response efforts difficult and severely taxed existing response plans . The region is a habitat for salmon, sea otters, seals and seabirds . The oil, originally extracted at the Prudhoe Bay oil field, eventually covered 1,300 miles (2,100 km) of coastline, and 11,000 square miles (28,000 km) of ocean . </P> <P> According to official reports, the ship was carrying 53,094,510 gallons (1,264,155 barrels) of oil, of which about 10.8 million US gallons (260,000 bbl; 41,000 m) were spilled into the Prince William Sound . An approximate figure of 11 million US gallons (260,000 bbl; 42,000 m) was a commonly accepted estimate of the spill's volume and has been used by the State of Alaska's Exxon Valdez Oil Spill Trustee Council, the National Oceanic and Atmospheric Administration and environmental groups such as Greenpeace and the Sierra Club . </P>

What caused the oil spill of exxon valdez