Glendora Mountain Road (GMR) Climb Guide

Overview

Glendora Mountain Road, known as GMR, is the favorite climb for riders across the San Gabriel Valley. It is a narrow mountain road that climbs from Glendora into the San Gabriels with big views back over the valley. It is moderate in grade but long, and it connects to Glendora Ridge Road, which leads to Mt. Baldy Village. It is a great training climb and a gateway to bigger days.

GMR is also one of the most-ridden climbs in the San Gabriel Valley, so you will rarely be alone on a weekend morning. Its steady grade makes it a favorite for pacing practice, and the views back over the valley improve with every switchback.

The route in plain words

Start in Glendora at the base of GMR near Big Dalton Canyon. The road climbs steadily through the foothills in a series of curves, with views opening up as you gain altitude. At the top, you can turn around and descend, or continue on Glendora Ridge Road toward Mt. Baldy Village for a longer adventure. OC Rides describes the ride from Glendora to Baldy Village as a classic route.

Distance and elevation

Strava's segment from the stop sign to the top lists about 14.78 km (9.2 miles), 726 m (about 2,382 ft) of gain and a 4.8% average grade. Bikeclimbs lists the GMR climb at 8.41 miles with 2,718 ft at 4.9%. Expect the round trip from Glendora to be about 18 to 20 miles.

Best time to ride

Ride in the morning, especially in summer. Fall and spring are ideal. Winter brings occasional closures after storms. Check fire and road status; GMR has had closures.

Water and coffee stops

There are no services on GMR. Glendora has cafés and shops at the base. If you continue to Mt. Baldy Village, the Mt. Baldy Lodge is a known stop.

Safety notes

GMR is narrow with blind corners and some fast drivers. Watch for rockfall, gravel and animals. Ride single file and use lights. Descend carefully.

Many riders descend GMR the same way they climbed. Descend at a speed that lets you stop in the distance you can see, especially on blind corners where cars or other cyclists may be climbing. Rockfall is common after storms and wind events, and road closures happen after fire and rain; check Los Angeles County road status before driving to the start.

Which bike and setup

A road bike with compact gearing suits GMR. Good brakes and fresh tires matter. A lightweight climbing bike makes the ride more pleasant.

Bring at least two bottles, since there is no water on the climb. If you plan to continue on Glendora Ridge Road toward Baldy, carry food, a spare tube, a pump and a light jacket.

Before you go

San Gabriel Valley riders, Veloaded is about an hour away. Ship your bike or drop it off for a tune-up. Call (714) 760-4908.

Quick facts

County: Los Angeles County
Start: Glendora Mountain Rd at Big Dalton Canyon Rd / Glendora Ave, Glendora
Distance: About 9.2 miles (14.78 km) from the stop sign to the top (Strava segment); another listing gives 8.41 miles
Climbing: About 2,382 ft (726 m) at about 4.8% (Strava); about 2,718 ft at 4.9% on a longer listing
Surface: Paved narrow mountain road
Difficulty: Hard; long moderate climb

Pair it with

GMR is the first half of the classic Glendora to Mt. Baldy ride via Glendora Ridge Road. For a longer mountain day further west, see Angeles Crest Highway.

Frequently asked questions

How long is the Glendora Mountain Road climb?

Strava's stop-sign-to-top segment lists about 9.2 miles with about 2,382 ft at 4.8%; Bikeclimbs lists 8.41 miles with 2,718 ft.

Can you ride from GMR to Mt. Baldy?

Yes. Glendora Ridge Road continues from the top toward Mt. Baldy Village; OC Rides describes the full Glendora to Baldy lifts ride at 53 miles and 7,604 ft.

Sources

Distances and climbing are from the published sources listed above and are approximate; roads, closures and conditions change. Check current conditions before you ride.

More Los Angeles County ride guides

All guides: Southern California ride guides. Veloaded Cyclery has one location, at 3420 W MacArthur Blvd Suite B, Santa Ana, CA 92704: service menu, bike fitting.