The killer Old Priest Grade Road in California hits a 20% of max gradient

Old Priest Grade Road is a very challenging route located in Tuolumne County, in the U.S. state of California. It’s extremely steep, with gradients reaching 20% on some ramps. Only passenger vehicles are allowed. Despite its potential dangers, the road offers stunning scenic views.

How long is Old Priest Grade Road?

Situated in the Western Sierra mountains, this winding and perilously steep mountain road spans 2.89km (1.8 miles), stretching from Moccasin, an unincorporated community in Tuolumne County, to Priest, a populated area located one mile southwest of Big Oak Flat.

Is Old Priest Grade Road paved?

The road is fully paved and has a rich history. Initially, it served as an Indian path and later became a wagon route. Constructed to facilitate stagecoaches and supply wagons for gold miners in the 1840s-1850s, the road was replaced by the New Priest Grade Road to the north in 1915.

Is Old Priest Grade Road dangerous?

Trucks, motorhomes, buses, and trailers are prohibited, with a 7,500-pound weight limit, restricting use to passenger vehicles. It's a steep and winding route, recommended only for drivers with reliable vehicles. The road has claimed 18 lives over the years, and it becomes slippery when wet. High rock slide risk is present, and the road is heavily traveled to Yosemite National Park. Winter weather exacerbates safety hazards, leading to icy conditions.

Is Old Priest Grade Road steep?

Ranked as one of Northern California's steepest climbs, the road features gradients up to 18%, with the steepest section possibly reaching 20%. Properly functioning brakes are essential, and overheating is a common concern during the steep ascent, particularly in the summer.