Text and photography copyright 2010 by David W. Lockeretz, all rights reserved. Information and opinions provided are kept current to the best of the author’s ability. All readers hike at their own risk, and should be aware of the possible dangers of hiking, walking and other outdoor activities. The author does not take any responsibility for injuries sustained during hikes or walks on the routes described here. Check the informational links provided for up to date trail condition information.
- Location: Foothills north of Glendora. Take I-210 to the Grand Ave. exit. Head north on Grand Ave for 1.9 miles and go right on Sierra Madre. After 1.5 miles, take a left on Loraine and follow it to its end, in half a mile. The Colby trail leaves from the end of the street. From Riverside and Orange County, take the 57 freeway to Auto Centre Dr (the last exit before it merges with I-210). Head left to Lone Hill, take a right and go 1.3 miles. Take a left on Foothill, go half a mile and take a right on Valley Center Ave. Go 0.8 miles and take a left on Sierra Madre. After half a mile, take a right on Loraine.
- Agency: City of Glendora
- Distance: 3 miles
- Elevation gain: 800 feet
- Difficulty Rating: PG
- Suggested time: 1.5 hours
- Best season: All year (hot during the summer)
- USGS topo map: “Glendora”
- More information: here; trail map here (not all trails shown)
- Rating: 6
This loop is similar to other trails in the San Gabriel foothills, such as those at Marshall Canyon and the Claremont Hills Wilderness Park. It offers nice views of the Inland Empire, the Santa Anas and on clear days downtown L.A. and the ocean.
From the end of Loraine, pick up the signed Colby Trail and head up into the canyon. The ascent is steady, but nice and cool under the shade of the oaks. Shortly, you come to a split. You can hike the route in either direction (this post describes my route, which was clockwise, although with the steep ascent ahead, you might want to consider the other direction.)
Take the center fork (the right fork will be your return route and the left, which passes through a stone wall, quickly becomes overgrown.) You soon exit the shade and climb quickly, taking in nice views of L.A. as you go, and after a mile, you reach the Colby Dalton trail. If you like, you can go a little higher and reach Glendora Mountain Road. If you’re winded, it’s understandable: you’ve gained almost 600 feet of elevation in just over a mile.
On your return, take the Colby Dalton Trail, which switchbacks down the slope, re-entering the shade. With its coolness and isolation, this is probably the most enjoyable part of the loop. (The only drawback is the noise from Glendora Mountain Road, which is not visible but located just beyond the dam.)
Finally the trail deposits you in front of the Dalton Dam. Head right on a paved road, around a corner and up a hill. Stay right the next split, and soon the pavement will end. Here, look for a dirt road branching off to the left, which heads back south toward civilization. A single-track will branch off to the right, which takes you through a meadow and back to the Colby Trail. Retrace your steps to complete the loop.
Glendora has a surprising number of trails, such as those in the South Hills Wilderness Area, and others in the Dalton Dam region. If you don’t have time to make it up to the Angeles National Forest or Big Bear Lake, you can certainly get your hiking fix here.