Thompson Ridge Road Climb
- long (28.7 km)
- 18 mi
- long (28.7 km)
- of climbing (1,249 m)
- 4,098 ft
- of climbing (1,249 m)
- average grade
- 4.4%
- average grade
- steepest 500 m
- 9.9%
- steepest 500 m
Elevation profile
From 1,726 ft at the bottom to 5,823 ft at the top. Grades are averaged over each half kilometre, from USGS elevation data, so short ramps can be steeper than they show.
Weather at the top of Thompson Ridge Road this week
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Is it safe to bike up Thompson Ridge 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.
Common questions about Thompson Ridge Road
- How long and steep is the Thompson Ridge Road climb?
- 18 miles (28.7 km) at 4.4% on average, climbing 4,098 ft (1,249 m) from 1,726 ft to 5,823 ft. The steepest half kilometre averages 9.9%. That makes it a Hors catégorie climb.
- Where does the climb start and finish?
- It starts at 41.79523, -123.3357, where Thompson Ridge Road leaves Happy Camp Dump Road, and tops out on the road at 41.99554, -123.40817.
- Is Thompson Ridge Road paved?
- Mostly: OpenStreetMap tags 67% of the climb as paved, and the rest as dirt or gravel.
- 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.
Other climbs nearby
- Fryingpan Ridge RoadHC · dirt · 12 mi at 5.4% · 3,409 ft · starts 1.3 mi away
- China Creek Road from China Grade RoadCat 1 · dirt · 6.7 mi at 6.1% · 2,149 ft · starts 1.6 mi away
- Doolittle RoadHC · dirt · 16 mi at 5.2% · 4,386 ft · starts 3.2 mi away
- Grayback RoadHC · 18 mi at 3.7% · 3,566 ft · starts 3.3 mi away
- East Fork Elk RoadHC · dirt · 10 mi at 5.6% · 3,005 ft · starts 3.4 mi away
- Thompson Creek RoadCat 3 · 2.4 mi at 6.5% · 814 ft · starts 4.6 mi away
- Bug Creek RoadHC · dirt · 6.8 mi at 8.5% · 3,054 ft · starts 5.7 mi away
- Clear Creek RoadCat 3 · 2.4 mi at 5.8% · 728 ft · starts 7.2 mi away
Found from OpenStreetMap roads and USGS 3DEP elevation; ranked on shape only. Hors catégorie: 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. Crashes: bike crashes reported within 100 ft of the climb, 2021–2025, from the California Crash Reporting System (CCRS), counted only where the report has map coordinates. Weather: National Weather Service. Access from OpenStreetMap tags; obey posted signs. How the data works.