Big Dipper 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 Big Dipper Road climb?

5.3 miles (8.5 km) at 4.5% on average, climbing 1,260 ft (384 m) from 2,552 ft to 3,812 ft. The steepest half kilometre averages 9.9%. That makes it a Category 2 climb.

Where does the climb start and finish?

It starts at 39.10626, -120.856, and tops out at Iowa Hill Road at 39.12841, -120.80618.

Is Big Dipper 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.

• Iowa Hill Road near ColfaxHC · 11 mi at 4.7% · 2,717 ft · starts 3.7 mi away
• Iowa Hill Road near ColfaxCat 2 · 2.9 mi at 7.7% · 1,194 ft · starts 3.7 mi away
• Elliot Ranch RoadCat 2 · 5.6 mi at 3.8% · 1,119 ft · starts 4.6 mi away
• Norton Grade RoadCat 3 · 3.0 mi at 5.1% · 810 ft · starts 4.9 mi away
• Rollins Lake RoadCat 3 · 3.0 mi at 5.4% · 856 ft · starts 5.0 mi away
• Sugar Pine RoadCat 3 · 3.4 mi at 4.1% · 738 ft · starts 5.0 mi away
• Yankee Jims RoadCat 1 · dirt · 7.6 mi at 5.6% · 2,270 ft · starts 5.2 mi away
• Chicago Park Powerhouse Road near ColfaxCat 3 · 3.2 mi at 4.1% · 705 ft · starts 5.2 mi away