South Hills Wilderness Area (Glendora)

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Alosta Canyon Trail, South Hills Wilderness Area
Alosta Canyon Trail, South Hills Wilderness Area
View from the South Hills Fire Road

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.

South Hills Wilderness Area (Glendora)

  • Location: Glendora.  From I-210, take the Grand Ave. exit north and take a quick right onto Baseline Road.  After 0.4 miles, take a left on Glendora, and a quick right on Mauna Loa.  The entrance to the park will be on your right in 0.5 miles.  Park on the street.
  • Agency: City of Glendora
  • Distance: 2.6 miles
  • Elevation gain: 750 feet
  • Difficulty Rating:  PG
  • Suggested time: 1.5 hours
  • Best season:  All year (hot during the summer)
  • USGS topo maps: “Glendora”
  • Recommended gear: hiking poles; insect repellent
  • More information: here; park map here; Everytrail report here
  • Rating: 6

Since this blog began back in May, I’ve written about many famous “must do” L.A. area hikes, and I’ve written about some that I had never heard of.  The South Hills Park in Glendora falls into that second category.  It’s in that small category that I nickname my “Mapquest” hikes: that is, a hike that I found while looking up directions for a different trail.  I was debating if I wanted to subject myself to the Garcia Trail to Azusa Peak (1,300 feet of elevation gain in 1.4 miles) and I noticed this large (200 acres) park on Mapquest.  It seemed big enough that it should have at least some hiking trails – and it does.  There are quite a few in fact, and the double loop that I pieced together here is only one of many possible trips you can take in this park.

From Mauna Loa, cross the playground and pick up the Toyon Trail which heads uphill.  Soon you come to a split.  The left route is your return; here you head right onto the Wild Iris trail which switchbacks its way up a ridge, gaining 200 feet in a quarter mile.  (A fire break runs up the hill as well; the Wild Iris trail crosses over it several times.)

You come to a T-junction with the Walnut Trail. Head right and follow the trail along a hillside with some nice views of Glendora, Azusa and the San Gabriel foothills. At 0.6 miles, you pass a water tank and reach another junction with the South Hills Motorway, the main trail through the park.

Head left, following the trail uphill and to the east, passing the other end of the Walnut Trail and a spur leading down to Bonnie Cove. You get great views of the Ontario/Cucamonga Ridge on the left, and if the day is clear, the L.A. basin, Santa Monica and Santa Ana Mountains on the right.  If you’re lucky, you might spot San Jacinto.

After passing by two fire roads branching off to the left (both of which will figure in your return route), the trail splits beneath a knoll where a few radio towers stand.  Take the left fork, and almost immediately look for the signed but obscure Alosta Canyon South Fork trail.  This trail, rough in some spots, steeply switchbacks down into the canyon.  It reminds me of a miniature version of the notoroius Fish Canyon Falls trail.

Soon, you arrive at the canyon bottom, and you pick up the Alosta Canyon Fire Road.  Take a left and ascend back to the main fire road.  Almost immediately take a right onto the signed North Spur (these are the two forks that you passed by earlier).  Make another quick left turn on the single-track Mustard Trail, which starts making its way down hill.

After about 0.2 miles, the trail makes a hairpin turn beneath a few big oaks, and splits.  The Mustard Trail continues, but you want to head left on the unsigned Toyon Trail, which heads downhill.  You pass under another grove of oaks before returning to the intersection with the Wild Iris trail.  Take a right and follow the Toyon Trail back to the parking area.

If the loop sounds a little involved, it’s actually pretty easy to follow, especially with the map.  Look for the signs and you’ll be fine.  The South Hills Wilderness Area was a pleasant surprise for me.  While it never really escapes the noise or sights of the nearby cities, and while it does suffer from some vandalism and litter, it’s yet another example of how it’s easy to have an enjoyable workout in nature if you know where to look.


  1. Thanks for your blog, very useful. My daughter and I studied it before we went. We took the alosta canyon trail, next time we’ll try the strenuous fork.

    1. Glad to hear you enjoyed the hike! I had heard that the park would be closed until June, but it seems like you guys were able to get in.

    1. That means that the next time you’re planning on a hike but decide not to go, you can go to the donut shop instead. Glad you enjoyed the hike!

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