Science Fair Project Encyclopedia
Copper River (Alaska)
The Copper River or Atna River is a river, approximately 300 mi (480 km) long, in southeast Alaska in the United States. It drains a large region of the Wrangell Mountains and Chugach Mountains into the Gulf of Alaska. It is known for its extensive delta ecosystem, as well as for its prolific runs of wild salmon, which are among the most highly prized stocks in the world.
It rises out of a glacier on the northwestern flank of the Wrangell Mountains, northeast of Mount Sanford in the Wrangell-Saint Elias National Park. It flows generally west around the north end of the Wrangell Mountains along the southwest edge of the Mentasta Mountains . At the north end of the Wrangells it flows generally southwest then southeast through a wide marshly plain to Chitina, where it is joined from the southeast by the Chitina River. Downstream from its confluence with the Chitina it flows southwest, passing through a narrow glacier-lined gap in the Chugach Mountains east of Cordova Peak . It enters the Gulf of Alaska approximately 50 mi (80 km) southeast of Cordova.
The name of the river comes for the abundant copper deposits along the upper river that were used by Alaskan Native population and then later by settlers from the Russian Empire and the United States. Extraction of the copper resources was rendered difficult by navigation difficulties at the river's mouth. The construction of the Copper River and Northwestern Railway from Cordova through the upper river valley in 1908-1911 allowed widespread extraction of the mineral resources, in particular from the Kennecott Mine , discovered in 1898. The mine was abandoned in 1938 and is now a ghost town tourist attraction. The Tok Cut-Off follows the Copper River Valley on the north side of the Chugach Mountains.
The river's famous salmon runs arise from the use of the river watershed by over 2 million salmon each year for spawning. The extensive runs result in many unique varieties. The Copper River Delta, which extends for 700,000 acres (2,800 km²) is the considered the largest contiguous wetlands along the Pacific coast of North America. It is used annually by 16 million shorebirds, including the world's entire population of western sandpipers. It is also home to the world's largest population of nesting trumpeter swans and is the only known nesting site for the dusky Canada goose.
The contents of this article is licensed from www.wikipedia.org under the GNU Free Documentation License. Click here to see the transparent copy and copyright details