Onion Valley climbs 12.9 miles (20.7 km) at an average of 7.7% from the corner of Webster Street and Onion Valley Road in Independence (3,944 ft / 1,202 m) to the end of the road at 9,177 ft (2,797 m), where the trails up to the Sierra crest begin. That’s 5,233 ft (1,595 m) of climbing with almost no letup. PJAMM rates it the hardest bike climb in California.
What the climb is like
It starts on the floor of the Owens Valley, one of the deepest valleys in the United States, wedged between mountains over 13,000 ft (4,000 m). The road climbs the wall of the Sierra with about ten hairpins. The grade is very steady: two-thirds of the route is between 5% and 10%, and about 2.2 miles (3.5 km) between 10% and 15%. The hardest mile (1.5 km) climbs at 11% and the steepest quarter mile (400 m) at 14.7%.
On some stretches there are expansion joints every few yards, which you notice most on the descent. In 2024 the guardrails were replaced on several sections.
PJAMM gives 12.9 miles (20.7 km) and 5,233 ft (1,595 m); Climbfinder, 13 miles (20.9 km) and 5,246 ft (1,599 m), with a maximum of 10.8% over 100 m.
When to go, services and altitude
The road is seasonal: it usually opens between May and June and closes in November, depending on snow. Before June or after September, check conditions on the Inyo County and Inyo National Forest websites. In summer a jersey is enough; in spring and fall it can be very cold and windy at the top.
There’s no water or food on the whole climb: stock up in Independence. Traffic is minimal.
The climb ends at almost 9,200 ft (2,800 m). If you live near sea level, spend a few days in the valley before you try it. The Owens Valley has one of the biggest concentrations of great climbs in the United States: about 15.5 miles (25 km) south, in Lone Pine, is Whitney Portal. Bishop and Lone Pine are the usual bases to stay in.
What gearing to use
With a constant 7-8% for more than an hour, a 34x32 is the reasonable minimum, and a 34x34 if you’re at 2.5 W/kg (watts per kilo of body weight) or below. Check your cadence in the gear calculator.
Frequently asked questions
How long does it take to bike up Onion Valley?
A 159 lb (72 kg) rider on a 21 lb (9.5 kg) bike takes about 1 h 49 min at 3 W/kg (216 W), 2 h 10 min at 2.5 W/kg and 1 h 23 min at 4 W/kg. Work out your own time with your weight and power in the calculator on this page.
When is Onion Valley Road open?
It's a seasonal mountain road: it usually opens between May and June and closes in November, depending on snow. Check Inyo County's open and closed roads page.
What gearing do you need for Onion Valley?
At least a 34x32. At 3 W/kg and 159 lb (72 kg), you'll ride about 6.8 mph (11 km/h) on 8%, and on the 12-14% ramps you'll drop to 4-4.7 mph (6.5-7.5 km/h): with a 34x32 that's about 50-57 rpm.