Humboldt Hill 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 Humboldt Hill Road climb?

1.7 miles (2.7 km) at 6.2% on average, climbing 541 ft (165 m) from 16 ft to 558 ft. The steepest half kilometre averages 8.1%. That makes it a Category 3 climb.

Where does the climb start and finish?

It starts at 40.73682, -124.20158, where Humboldt Hill Road leaves Rolica Circle, and ends where the road ends at 40.71442, -124.20139.

Is Humboldt Hill 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.

• Berta RoadCat 3 · 1.2 mi at 8.4% · 541 ft · starts 1.6 mi away
• Tompkins Hill Road near FortunaCat 3 · 4.5 mi at 3.1% · 738 ft · starts 3.7 mi away
• Greenwood Heights DriveCat 2 · 6.5 mi at 5.8% · 1,978 ft · starts 7.2 mi away
• Kneeland Road from Freshwater RoadHC · 9.2 mi at 5.6% · 2,730 ft · starts 8.1 mi away
• Tompkins Hill Road from Palmer Creek RoadCat 3 · 1.7 mi at 7.7% · 676 ft · starts 9.1 mi away
• Garden LaneCat 3 · 0.9 mi at 16% · 761 ft · starts 11 mi away
• Splinter RoadCat 3 · 1.0 mi at 14.3% · 725 ft · starts 11 mi away
• Barry RoadCat 3 · 2.4 mi at 4.4% · 561 ft · starts 11 mi away