In 1852, the Sonora Road was opened from the Carson Trail to Sonora, California, by the Clark-Skidmore Company.
 From the Humboldt Sink it crossed Forty Mile Desert to the Carson River and then went almost due south to the Walker River, which it followed to the Sierras before making the very steep (about 26 degrees in parts) and rugged ascent to 9,625 feet (2,934 m) Sonora Pass.

From there the road drops down twisting forested mountain ridges to Sonora.
This was the highest road developed across the Sierras—and still a very scenic drive. (
modern Tioga Pass out of Yosemite National Park is slightly higher) California State Route 108 between Sonora and U.S. Highway 395 roughly approximates the route of the Sonora Road over the Sierras.
This route was little used after about 1854.
In 1852, the Sonora Road was opened from the Carson Trail to Sonora, California, by the Clark-Skidmore Company.  From the Humboldt Sink it crossed Forty Mile Desert to the Carson River and then went almost due south to the Walker River, which it followed to the Sierras before making the very steep (about 26 degrees in parts) and rugged ascent to 9,625 feet (2,934 m) Sonora Pass.
From there the road drops down twisting forested mountain ridges to Sonora. This was the highest road developed across the Sierras—and still a very scenic drive. (modern Tioga Pass out of Yosemite National Park is slightly higher) California State Route 108 between Sonora and U.S. Highway 395 roughly approximates the route of the Sonora Road over the Sierras. This route was little used after about 1854.
California Trail