 State Route 70 | ||||
|---|---|---|---|---|
 SR 70 highlighted in red | ||||
| Route information | ||||
| Maintained by Caltrans | ||||
| Length | 178.528 mi[1] (287.313 km) (plus about 0.5 mi (1 km) on SR 20) | |||
| History | State highway in 1910 and 1931; became SR 24 in 1934, US 40A in 1954, and SR 70 in 1964 | |||
| Tourist routes |  Feather River Scenic Byway | |||
| Major junctions | ||||
| Southwest end |  SR 99 near Pleasant Grove | |||
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| Northeast end |  US 395 at Hallelujah Junction | |||
| Location | ||||
| Country | United States | |||
| State | California | |||
| Counties | Sutter, Yuba, Butte, Plumas, Lassen | |||
| Highway system | ||||
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State Route 70 (SR 70) is a state highway in the U.S. state of California, connecting SR 99 north of Sacramento with U.S. Route 395 (US 395) near Beckwourth Pass (lowest in the Sierra Nevada) via the Feather River Canyon. Through the Feather River Canyon, from SR 149 to US 395, SR 70 is the Feather River Scenic Byway, a Forest Service Byway that parallels the ex-Western Pacific Railroad's Feather River Route.
The Beckwourth Trail was the earliest predecessor of SR 70, which was a spur of the California Trail. This was followed by the railroad, mostly built on the route of the trail; a dirt road was needed for construction that was later converted into part of the present state highway. Construction on the highway began in 1928, which involved the boring of three tunnels. Previously, the road was signed as U.S. Route 40 Alternate, crossing the Sierra Nevada at a lower elevation than Donner Pass on US 40, now Interstate 80 (I-80). The road was renumbered SR 70 in the 1964 state highway renumbering. Today, portions of SR 70 have been upgraded to a four-lane expressway, and even a freeway in a few locations.