Warthan Canyon Climb

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 Warthan Canyon climb?

4.9 miles (7.9 km) at 3.2% on average, climbing 827 ft (252 m) from 1,693 ft to 2,520 ft. The steepest half kilometre averages 8.9%. That makes it a Category 3 climb.

Where does the climb start and finish?

It starts at 36.12489, -120.5985, and tops out on the road at 36.16729, -120.66446.

Is Warthan Canyon 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.

• Smith Mountain Lookout RoadCat 2 · 4.9 mi at 7.6% · 1,982 ft · starts 5.1 mi away
• Parkfield GradeCat 1 · 9.0 mi at 5% · 2,369 ft · starts 7.2 mi away
• South San Joaquin Rocks Lookout RoadHC · dirt · 9.5 mi at 5.6% · 2,782 ft · starts 8.7 mi away
• Mustang GradeCat 3 · 3.0 mi at 3.7% · 584 ft · starts 8.8 mi away
• Derrick RoadCat 1 · 7.9 mi at 5.4% · 2,254 ft · starts 9.6 mi away
• Pancho Rico RoadCat 2 · 7.9 mi at 3.1% · 1,283 ft · starts 13 mi away
• South Joaquin Ridge Lookout RoadHC · dirt · 9.8 mi at 5.5% · 2,848 ft · starts 13 mi away
• Oil City RoadCat 2 · 6.0 mi at 3.9% · 1,243 ft · starts 15 mi away