Crescent River is formed by the junction of the North Fork and Lake Fork tributaries, which start in Lake Clark National Park and Preserve, and flows south-east for 12 miles (19 km) to the northern shore of Tuxedni Bay on the western coast of Cook Inlet, about 55 miles (89 km) north-west of Homer and 51 miles (82 km) south-west of Kenai, Alaska. The local name was first reported in 1958 by the US Geological Survey and is taken from Crescent Lake, which lies along Lake Creek. Lake Creek starts from an unnamed glacier at an elevation of about 5,000 feet (1,524 m) on the south-eastern flank of the Chigmit Mountains and flows 9 miles (14.5 km) to Crescent Lake, which is about 6 miles (10 km) long, and then another 4 miles (6.4 km) to Crescent River. The watershed covers approximately 160,000 acres (64,750 ha).

The entire Crescent River watershed lies within Lake Clark National Park and Preserve. Public lands include Crescent Lake, the headwaters above the lake and the upper portion of the North Fork. The Crescent River system contains all five species of Pacific salmon, with sockeye salmon being the most important to the Cook Inlet commercial salmon industry. Sport fishermen also target the fish, and local rural residents use the rivers as a traditional subsistence fishery. The Alaska Department of Fish and Game has maintained a sonar fish-counter on the river since 1979, and sockeye counts have ranged from about 20,000 to about 200,000 fish per year. Crescent River sockeye are managed under a biological escapement goal of 30,000 to 70,000 fish. Most of the salmon travel up the Lake Fork into Crescent Lake and spawn along its shores and tributaries.

Cook Inlet Region Incorporated and three Alaska Native village corporations own large tracts of inholdings in the watershed along the North Fork and between Crescent Lake and Cook Inlet. Timber rights to approximately 42,000 acres (16,997 ha) of the lower Crescent River watershed were sold to a logging company in 1997. From 1998 to 1999 the timber company built a primary access road, airstrip and log-transfer facility, including a causeway extending 550 feet (168 m) into Tuxedni Bay. Secondary roads were built to harvest timber on the west side of the river, and between 2000 and 2001 about 700 acres (283 ha) were logged. The potential effects of logging on the water quality of streams include increasing stream temperature due to sunlight exposure, river sedimentation due to soil disturbance, riparian vegetation removal affecting streambank integrity, and spawning habitat loss. If logging resumed at the planned scale, the result could pose an imminent threat to the water quality and fish habitat of the Crescent River watershed. Read more here and here. Explore more of Crescent River and Lake Clark National Park and Preserve here: