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. Route description State Route 70 begins at a partial interchange with SR 99 north of Sacramento, close to the Feather River Route rail line that parallels the entire highway, and heads north along a four-lane mix of expressway and freeway. Just north of the Bear River crossing / Yuba County line, in Plumas Lake, SR 70 becomes a freeway for the second time, which continues to just beyond the Yuba River in Marysville. Within that city, SR 70 makes two turns and overlaps SR 20 before heading north on a two-lane road. Another four-lane freeway begins south of SR 162 in Oroville, and ends at SR 149. SR 149 is a major connection northwest to SR 99, and became the straight-through movement when the construction to replace the intersection with an interchange was completed in November 2008. The State Scenic Highway portion of SR 70 begins at SR 149, which is where SR 70 turns northeast out of the Sacramento Valley and into the mountains. The short SR 191 spurs north to Paradise, while SR 70 crosses the West Branch Feather River on the double-decker West Branch Bridge, with the Feather River Route below. A short four-lane section runs over the bridge towards Jarbo