Old Mammoth 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 Old Mammoth Road climb?

3.2 miles (5.2 km) at 5.3% on average, climbing 899 ft (274 m) from 7,854 ft to 8,753 ft. The steepest half kilometre averages 9.2%. That makes it a Category 3 climb.

Where does the climb start and finish?

It starts at 37.63552, -118.96658, where Old Mammoth Road leaves Mammoth Creek Road, and tops out at Lake Mary Road at 37.61524, -119.00288.

Is Old Mammoth 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.

• Minaret RoadCat 2 · 6.8 mi at 3.6% · 1,280 ft · starts 0.3 mi away
• Lakes Basin PathCat 3 · 2.7 mi at 4.4% · 620 ft · starts 1.3 mi away
• Lake Mary RoadCat 3 · 3.5 mi at 5.2% · 961 ft · starts 1.3 mi away
• Main Street near Mammoth LakesCat 3 · 3.1 mi at 3.4% · 554 ft · starts 2.0 mi away
• Laurel Mountain TrailHC · dirt · 4.6 mi at 11.4% · 2,756 ft · starts 3.4 mi away
• Mammoth Scenic LoopCat 3 · 4.1 mi at 3.8% · 817 ft · starts 5.1 mi away
• Minaret Summit RoadCat 3 · 3.2 mi at 3.8% · 646 ft · starts 6.0 mi away
• Postpile RoadCat 3 · 2.3 mi at 6.8% · 837 ft · starts 6.8 mi away