American River
The North Fork is the longest tributary of the American River, at . It begins at an elevation of about near Lake Tahoe in Placer County at Mountain Meadow Lake, just northeast of Granite Chief and immediately due west of Squaw Valley Ski Resort. It flows westward through remote wilderness areas.
South Fork Trinity River
The river and its tributaries drain in Humboldt County in the south and Trinity County in the north, comprising 34 percent of the Trinity River watershed. The Hayfork Creek sub-watershed contains , or 38 percent of the entire South Fork Trinity watershed. Most of the watershed lies on public lands (79 percent), while for Hayfork Creek, 78 percent of its watershed lies on public lands. With the Yolla Bolly Mountains in the south and the Klamath Mountains in the north, the topography of the South Fork Trinity's watershed is dissected by deep gorges and valleys separated by narrow ridges. The South Fork is the longest undammed National Wild and Scenic River in California. (The Eel River, also a Wild and Scenic River, is over twice as long, but is dammed near its headwaters. The Smith River drains a greater area but is much shorter.)