By the late 1910s, a "natural prairie road" linked Oroville to State Highway Route 3 southeast of Chico, following the present Table Mountain Boulevard, Openshaw Road, and Oroville-Chico Highway to Midway (Route 3). The primary route between these two cities was the all-state highway route, following Route 21 (now SR 162) west from Oroville to Route 3 near Richvale. Butte County dedicated a newly improved Oroville-Chico Highway on July 4, 1926; it became part of the state highway system in 1933 as the northern portion of the Woodland-Chico Route 87. (The rest of Route 87 became part of Sign Route 24, which turned east at Oroville along present State Route 70, in 1934.)