Los Angeles driving guide · Technical mountain & canyon
Glendora Mountain Road to Highway 39
GMR brings the tight turns and mountain views. Stay on it over the ridge and down to East Fork Road, then follow Highway 39 back toward Azusa for a more open canyon finish.
Confirm vehicle access on GMR and East Fork before starting. Mountain gates can close for weather, fire restrictions or holidays; this guide is not a live open-road report. Check vehicle access ↗
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Road overview, not turn-by-turn navigation. Follow the junctions below; some catalog traces extend beyond the written drive. Use two fingers to move the map.
- Glendora Mountain Road north
- East Fork Road west
- Highway 39 south
- Start
- Glendora Mountain Road at Big Dalton Canyon Road
- Finish
- Highway 39 at the Azusa foothills
- Return
- Return options below ↓
Why this drive
The contrast is the draw. GMR is the involved part: repeated tight bends, changing sightlines and a climb followed by a descent. East Fork eases you into the canyon, and lower Highway 39 has a more flowing, everyday highway feel as it heads toward town. The character changes, but there are still bends, cyclists and traffic to account for throughout.
The route
Glendora Mountain Road: climb, then descend to East Fork
Begin at Big Dalton Canyon Road on the Glendora side and head uphill on GMR. At the Glendora Ridge Road junction, keep left on Glendora Mountain Road toward East Fork; the right branch goes toward Mount Baldy. Continue down the north side to East Fork Road. This climb and descent make up the technical section.
Glendora Mountain Road · GMR & map →East Fork Road west to Highway 39
At the foot of GMR, follow East Fork Road west toward Highway 39 / San Gabriel Canyon Road. This is the connecting road between GMR and 39; keep on East Fork through the canyon rather than taking the Shoemaker Canyon spur.
East Fork Road & map →Highway 39 south to Azusa
At Highway 39, turn left toward Azusa. Follow San Gabriel Canyon Road south past the reservoirs to the foothills. The wider-feeling curves and return toward town give this section a more flowing, commuter-road character than GMR. This guide uses lower Highway 39, not the northern extension toward Crystal Lake or Angeles Crest.
San Gabriel Canyon Road · SR 39 & map →
Good places to stop
Glendora
Get fuel, food and water in town before starting the mountain section.
GMR viewpoints
The mountain views are a reason to pause. Use an open, legal pullout with enough room to leave the road completely; keep gates and junctions clear.
Azusa
A convenient food stop at the end of the canyon section, before returning to Glendora or heading home.
The way back
The mountain drive finishes in the Azusa foothills. Continue into Azusa and use the local street network or I-210 east to return to Glendora. That urban return is separate from the three mountain-road sections highlighted here.
Road conditions
Check LA County’s vehicle closures and Angeles National Forest alerts for GMR and East Fork. Caltrans lists Highway 39 closed from two miles north of Crystal Lake Road to Highway 2; that northern closure is beyond this southbound itinerary. Pavement condition can change after storms, so an older report of smooth pavement is not a guarantee for today.
Expect drivers, motorcycles and cyclists, especially at popular junctions and stops. Give people space, follow posted limits and check current access before setting off.
Route references
- Autoblog: GMR, East Fork and the return to Azusa (2009 route report) ↗
- Carl Pulley: GMR junctions and road character (June 2026) ↗
- OpenStreetMap: Glendora Mountain Road ↗
- Caltrans: Highway 39 conditions ↗
Guide updated September 13, 2026. Route descriptions cover the named sections; check current access before travelling.