Kuskokwim River - Course

Course

The river is formed by the confluence of East Fork Kuskokwim River and North Fork Kuskokwim River, 5 miles (8 km) east of Medfra. From there it flows southwest to Kuskokwim Bay and the Bering Sea.

The Kuskokwim is fed by several forks in central and south-central Alaska. The North Fork (250 mi/400 km) rises in the Kuskokwim Mountains approximately 200 miles (320 km) WSW of Fairbanks and flows southwest in a broad valley. The South Fork (200 mi/320 km) rises in the southwestern end of the Alaska Range west of Mount Gerdine and flows north-northwest through the mountains, past Nikolai, receiving other streams that descend from the Alaska Range northwest of Mount McKinley. The two forks join near Medfra, and from there the main stem of the Kuskokwim flows southwest, past McGrath, in a remote valley between the Kuskokwim Mountains to the north and the Alaska Range to the south.

In southwest Alaska the river emerges from the Kuskokwim Mountains in a vast lake-studded alluvial plain south of the Yukon River, surrounded by vast spruce forests. It passes a series of Eskimo villages, including Aniak, and approaches within 50 mi (80 km) of the Yukon before diverging southwest. Southwest of Bethel, the largest community on the river, it broadens into a wide marshy delta that enters Kuskokwim Bay approximately 50 mi (80 km) SSW of Bethel. The lower river below Aniak is located within the Yukon Delta National Wildlife Refuge.

The river receives the Big River from the south approximately 20 miles (32 km) southwest of Medfra. It receives the Swift, Stony, and Holitna rivers from the south at the southern end of the Kuskokwim Mountains before emerging on the coastal plain. It receives the Aniak River from the south at Aniak. Approximately 20 miles (32 km) upstream from Bethel it receives the Kisaralik and Kwethluk rivers from the south. It receives the Eek River from the east at Eek near its mouth on Kuskokwim Bay.