ⓘ California State Route 20
State Route 20 is a state highway in the northern-central region of the state of California, running east–west north of Sacramento from the North Coast to the Sierra Nevada. Its west end is at SR 1 in Fort Bragg, from where it heads east past Clear Lake, Colusa, Yuba City, Marysville and Nevada City to I-80 near Emigrant Gap, where eastbound traffic can continue on other routes to Lake Tahoe or Nevada.
Part of SR 20 are built near the road that was first a wagon road and then highway in the late 19th century. This road was extended in the framework of the state highway system, to ukiah in the early 20th century, and the missing link near clear lake was completed in 1932 before the official designation on this road, as SR 20 in 1934. There have been subsequent improvements on the road, such as the conversion of the grass part of the route to freeway standards.