Portal:California roads/Selected article/29

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. Portions of SR 20 are built near the routing of what was first a wagon road and later a turnpike in the late nineteenth century. This road was extended through the state highway system all the way to Ukiah in the early twentieth century, and the missing link near Clear Lake was completed in 1932 before the official designation of this highway as SR 20 in 1934. There have been subsequent improvements to the road, such as the conversion of the Grass Valley portion of the route to freeway standards.