Copper River drains much of eastern-south central Alaska. When ranked by average discharge volume the Copper River ranks tenth largest river in the United States. Copper River is best known for its salmon which has been considered some of the best in the world. Like all glacier fed rivers of Alaska, the Copper River is not clear, but milky-grey as it carries high percentages of silt.
Chinook or king salmon are present May - June, sockeye or red salmon May - August, and coho or silver salmon August - September.
Each spring, an estimated 12 million shorebirds, the largest gathering of shorebirds in the western hemisphere, stop along the shores of the Copper River Delta on their way to more northern nesting grounds. Among these migrants are nearly the entire Pacific coast population of dunlins and western sandpipers, and large numbers of least sandpipers, knots, and short and long-billed dowitchers. During peak migration periods from late April through May, concentrations of up to 250,000 shorebirds per square mile have been observed feeding on the Copper River Delta tideflats. Millions of ducks, geese, and swans, including white-fronted and Canada geese, pintails, green-winged teal, American wigeon, shoveler, greater scaup, common and Barrow's goldeneye, oldsquaw, bufflehead, and trumpeter and tundra swans, rest and feed on the delta during spring migration. Despite the six-foot uplift of the delta's wetlands during the 1964 earthquake and the resulting drying of some lands, the delta remains a productive summer nesting habitat for thousands of waterbirds, including a major portion of the world's population of dusky Canada geese; over ten percent of the world's trumpeter swans; dabbling ducks; mergansers; and red-throated loons.
Copper River is named such because of the abundant copper deposits along upper portions of the river.