The Mulchatna River (Dena'ina: Vałts'atnaq') is a 160-mile (260 km) tributary of the Nushagak River in the U.S. state of Alaska. Beginning at Turquoise Lake, it flows generally southwest to meet the larger river 65 miles (105 km) northeast of Dillingham. The Mulchatna's mouth is slightly south (downstream) of the village of Koliganek on the Nushagak, which continues southwest to Nushagak Bay, an arm of Bristol Bay.

Lake Clark National Park and Preserve is an American national park in southwest Alaska, about 100 miles (160 km) southwest of Anchorage. The park was first proclaimed a national monument in 1978, then established as a national park and preserve in 1980 by the Alaska National Interest Lands Conservation Act. The park includes many streams and lakes vital to the Bristol Bay salmon fishery, including its namesake Lake Clark. A wide variety of recreational activities may be pursued in the park and preserve year-round. The park protects rainforests along the coastline of Cook Inlet, alpine tundra, glaciers, glacial lakes, major salmon-bearing rivers, and two volcanoes, Mount Redoubt and Mount Iliamna. Mount Redoubt is active, erupting in 1989 and 2009. The wide variety of ecosystems in the park mean that virtually all major Alaskan animals, terrestrial and marine, may be seen in and around the park. Salmon, particularly sockeye salmon, play a major role in the ecosystem and the local economy. Large populations of brown bears are attracted to feed on the spawning salmon in the Kijik River and at Silver Salmon Creek. Bear watching is a common activity in the park.