Adit 4 Road 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 Adit 4 Road climb?

2.1 miles (3.4 km) at 8.8% on average, climbing 971 ft (296 m) from 2,631 ft to 3,602 ft. The steepest half kilometre averages 10.9%. That makes it a Category 3 climb.

Where does the climb start and finish?

It starts at 38.15479, -120.39202, and tops out at Wylderidge Drive at 38.16544, -120.38322.

Is Adit 4 Road 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.

• Peppermint LaneCat 3 · 1.5 mi at 7.8% · 623 ft · starts 1.8 mi away
• Camp Nine RoadCat 2 · 5.4 mi at 4% · 1,152 ft · starts 2.1 mi away
• Ponderosa Way from Skunk Ranch RoadCat 3 · 2.1 mi at 5.9% · 666 ft · starts 2.7 mi away
• Skunk Ranch RoadCat 3 · 2.2 mi at 6.8% · 778 ft · starts 2.7 mi away
• Ponderosa Way from Camp Nine RoadCat 3 · 2.1 mi at 9.2% · 1,004 ft · starts 2.9 mi away
• Mount Davis RoadCat 3 · 0.9 mi at 12.2% · 584 ft · starts 3.0 mi away
• Crestview RoadCat 3 · 1.3 mi at 9.9% · 659 ft · starts 3.2 mi away
• Pennsylvania Gulch RoadCat 3 · 4.3 mi at 4.3% · 984 ft · starts 3.3 mi away