At 8,696 feet, Ontario Peak is one of several peaks in the San Gabriel Mountains, and lies within the Cucamonga Wilderness. It is one of the many peaks near Mt. Baldy which are accessible from the Icehouse Saddle. It is named after the nearby city of Ontario. On a clear day, Ontario Peak offers sweeping views of the spectacular San Gabriel Mountains, the Inland Empire, Los Angeles, Orange County and Pacific Ocean.
Getting to Trailhead
Start at the popular Icehouse Canyon Trailhead. There’s plenty of parking, but it fills up fast. Make sure to head out early before the crowds. We started our hike at 6:30 am. An Adventure Pass is required.
To the left of the trailhead, next to the sign, is a box for self-serve permits (bring a pen with you). Fill one out and leave white copy in the box, take yellow copy with you.
Hiking the Trail to Ontario Peak
Hiking up the Icehouse Canyon is a beautiful hike on its own. It is a well-traveled trail, with a creek that meanders alongside it. Surrounded by sugar pine forest, which shades the trail during the Summer months, massive boulders, canyon walls, and mountain peaks line up the trails. And if you’re lucky enough, you may see some of the resident big horn sheep.
Continue hiking up to 3.5 miles to the Icehouse Saddle, gaining 2,700 feet. Once there, it is a good spot for a quick break before you head up to the peak. At the saddle, you will find several trails with signs that lead to Cucamonga Peak, 3 Ts, Middle Fork, and Ontario Peak, which is to the right of the saddle.
From here, it’s a gentle climb for 1.0 mile to Kelly Camp, gaining only 260 feet.
Kelly Camp is a great spot to camp if you’re doing an overnight. This can be crowded though, especially on weekends. It is a historical place with remnants of foundations of a former trail resort. This was once owned by John Kelly, who built it in 1905 as a mining prospect, then turned into a trail resort in 1922 by Henry Delker. There is a spring nearby, but it is unreliable.
The trail continues on beyond the Kelly Camp ruins, then climbs up to a fire-scarred Ontario ridge. At this point, you will have the dramatic view of Timber Mountain, Telegraph Peak and Mt. Baldy.
If squint your eyes, you may even see the tiny blue-green speck of the Ski Hut just below Baldy Notch. As you continue your ascent, you will come upon a fork on the trail with a pile of rocks and a wooden sign that points to Bighorn Peak to the left and Ontario Peak to the right.
This is also a great spot for picture, with a panoramic view of the Inland Empire and beyond Orange County, with the Saddleback Mountain protruding from the distance. You will also have dramatic view of Bighorn Peak to the left and Cucamonga Peak on the right.
Continue following the trail as it contours around the two false summits, then zig-zagging up a series of switchbacks.
Eventually, you will arrive on a ridge again to continue your rather steep approach to the summit, but it levels out at 150 yards before Ontario Peak.
At the summit, you’ll find a large dead tree, which has become the landmark for Ontario Peak, and a tall heap of boulders. On a clear day, you’ll sweeping views of Inland Empire, Los Angeles and the Pacific Ocean.
On the way back, we took the spur trail to the summit of Bighorn Peak. This added about two miles to the trip, but gave us one more peak to add to our resume. If you decide to include the spur to Bighorn, the total mileage jumps to over 14 miles total. The elevation profile and map below show this additional mileage.
Ontario and Bighorn Peaks Trail Map & Elevation Profile
Tips & Tricks for Hiking Ontario Peak
- Go early to get first dibs on parking. An Adventure Pass is required for parking.
- There is a restroom at the parking lot area.
- Mind your steps. Though Icehouse Canyon Trail is picturesque, the first 2 miles of the trail surface has uneven footing and a lot of loose rocks which can make it slippery.
- Bring sun protection. Once above the tree line, you are fully exposed to the sun.
- Carry at least 3 liters of hydration. There are springs along the trail, it will need to be filtered and Kelly Camp spring is unreliable.
- If you’re camping overnight at Kelly Camp, you will share it many others, especially on weekends.
Ontario Peak Weather Forecast
Originally hiked on January 6, 2018 with Hike Beyond the Hills.