State Route 20 (SR 20) is a state highway in the northern central region of the U.S. state of California, running east–west across the state north of Sacramento. 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.