Prince William Sound is a body of water in the Gulf of Alaska. A sound is a small body of water that comes in from the ocean. Prince William Sound is on the south side of the U.S. state of Alaska. It is on the east side of the Kenai Peninsula. Its biggest port is Valdez, at the south end of the Trans-Alaska Pipeline System. Other towns on the sound include Cordova and Whittier.
James Cook went in Prince William Sound in 1778. He named it Sandwich Sound, after the Earl of Sandwich. The Sound's name was changed in the same year. It was then named after George III's third son Prince William Henry. Prince William was then 13 years old. He was in the Royal Navy.
Most of the land near Prince William Sound is part of the Chugach National Forest. Chugach is the second largest U.S. National Forest. Prince William Sound is ringed by the Chugach Mountains. These mountains are steep. The coast is complex. It has many islands and fjords. It also has some glaciers.
In 1989, the oil tanker Exxon Valdez ran aground. It caused a large oil spill, which damaged the environment. It killed around 250,000 seabirds, nearly 3,000 sea otters, 300 harbor seals, 250 bald eagles and up to 22 killer whales.