State Highway 108 Climb from Mono Vista Road

We don't rate roads as safe or unsafe: crash counts can't say how risky a ride is, and roads people like to ride draw more riders, so they see more crashes. What the records show: no bike crashes were reported along the climb from 2021–2025.

How long and steep is the State Highway 108 from Mono Vista Road climb?

2.9 miles (4.7 km) at 5.2% on average, climbing 810 ft (247 m) from 2,890 ft to 3,701 ft. The steepest half kilometre averages 7.1%. That makes it a Category 3 climb.

Where does the climb start and finish?

It starts at 37.99118, -120.27771, where State Highway 108 leaves Mono Vista Road, and tops out at Sonora Pass Highway at 38.02183, -120.24373.

Is State Highway 108 paved?

Yes, by its OpenStreetMap tags.

How is the category worked out?

From the climb's shape only: length in metres × average grade (%) of 16,000 or more for Cat 3, 32,000 for Cat 2, 64,000 for Cat 1 and 80,000 for HC. It describes how hard the climb is, not traffic or crashes.

Where does this data come from?

The climb is found from OpenStreetMap roads and USGS 3DEP elevation (every climb, not a list of famous ones). Access is from OpenStreetMap tags; gates and closures change, so obey posted signs. Crash counts are police reports in the California Crash Reporting System (CCRS) on data.ca.gov, counted where their map location is within 100 ft of the climb. The forecast is from the National Weather Service.

• Paseo de Los Portales RoadCat 3 · 1.8 mi at 7.7% · 745 ft · starts 1.8 mi away
• Ridgewood DriveCat 3 · 2.1 mi at 6.5% · 702 ft · starts 2.0 mi away
• Phoenix Lake RoadCat 3 · 4.1 mi at 3.8% · 830 ft · starts 2.0 mi away
• Avenida del SolCat 3 · 1.7 mi at 7.4% · 646 ft · starts 2.0 mi away
• Montgomery RoadCat 3 · 2.0 mi at 6.6% · 692 ft · starts 2.1 mi away
• Tuolumne Road NorthCat 2 · 6.7 mi at 3.6% · 1,289 ft · starts 2.7 mi away
• Middle Camp RoadCat 3 · 2.6 mi at 4.8% · 650 ft · starts 2.9 mi away
• Kewin Mill RoadCat 3 · 1.7 mi at 7.7% · 679 ft · starts 3.2 mi away