The North Fork Feather River is a watercourse of the northern Sierra Nevada and southern Cascades in the U.S. state of California. It flows generally southwards from its headwaters near Lassen Peak to Lake Oroville, a reservoir formed by Oroville Dam in the foothills of the Sierra, where it runs into the Feather River. The river drains about 2,100 square miles (5,400 km2) of the western slope of the Sierras. By discharge, it is the largest tributary of the Feather.

The Sierra Nevada is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primarily in Nevada. The Sierra Nevada is part of the American Cordillera, an almost continuous chain of mountain ranges that forms the western "backbone" of the Americas.