California State Route 36 passes through Fredonyer Pass. The pass is west of Susanville, California and southeast of Mount Lassen. The pass is an approximate northern boundary between the Sierra Nevada and the Cascade Range. This irregular boundary is sometimes defined as the southern extent of Cenozoicigneous surface rock from the Cascade range[2] (http://www.consrv.ca.gov/cgs/information/publications/cgs_notes/note_36/note_36.pdf). This boundary roughly follows the drainage of the North fork of the Feather River southwest from Fredonyer Pass. Note that there are other Cenozoic igneous rocks in the Sierra (e.g., near Lake Tahoe), but there is a clear geological division near Fredonyer Pass.
External links
California Geological Survey - Geologic maps (http://www.consrv.ca.gov/cgs/information/geologic_mapping/index.htm)
See also: Principal passes of the Alps, List of mountain passes in Switzerland.
Fremont Pass (California), separating the San Gabriel Mountains from the Santa Susana Mountains
Trail Ridge Road includes Milner Pass (10,120 ft/3,085 m), but elsewhere attains an elevation of 12,183 ft (3,713 m), making it the highest paved road in the United States.