Telegraph Peak Hiking Guide
Telegraph Peak is the high point of the Three Ts and one of the more demanding day hikes in the eastern San Gabriels. Reached from Icehouse Saddle by way of the ridge past Timber Mountain, it tops out above 8,900 feet with a view straight across at the Baldy massif — close enough that the Devil's Backbone traces visibly along the skyline. Thirteen miles and roughly 4,700 feet of cumulative gain at altitude makes this a full day that rewards fitness and punishes optimism.
Permit: Cucamonga Wilderness permit required for the Icehouse Canyon approach; free self-issue permits at the Mt Baldy Visitor Center
Permit and Approach
Like everything reached through Icehouse Canyon, this route requires a free Cucamonga Wilderness permit, historically self-issue at the Mt Baldy Visitor Center. Handle it before you start. The approach follows Icehouse Canyon past the cabin ruins and up the switchbacks to Icehouse Saddle at about 7,600 feet — roughly three and a half miles and the bulk of the pleasant walking. From the saddle you commit to the ridge, and the character of the day changes.
The Ridge Climb
From the saddle the trail climbs toward Timber Mountain, then continues along the ridge, dropping and regaining elevation before the final steep push up Telegraph. That undulating profile is what makes the total gain so much higher than a simple summit calculation suggests — you pay for elevation more than once. The upper slopes are steep, loose in places, and increasingly exposed as the forest thins. The last stretch to the summit is a real grind at nine thousand feet.
The Summit View
Telegraph's top is one of the best viewpoints in the range. Mount Baldy fills the western sky with the Devil's Backbone ridge clearly visible, the Cucamonga Wilderness peaks stack up to the east, and the Mojave stretches north beyond the crest. To the south the Inland Empire spreads out under whatever haze the day has produced. On clear post-storm days the visibility here is exceptional. Wind is common and there is little shelter, so pack a layer regardless of the forecast at the trailhead.
Difficulty Honestly Stated
This is a hard day. The combination of thirteen miles, roughly 4,700 feet of cumulative gain, an 8,900-foot summit, and an undulating ridge that makes you climb the same ground twice means hikers who comfortably handle ten-mile foothill days often struggle badly here. Start at dawn. Budget substantially more time than your usual pace suggests. Turning back at Timber Mountain or Icehouse Saddle is a perfectly good outcome and far better than being caught high on the ridge late in the day.
Season, Water, and Weather
Summer and fall only, unless you are equipped for snow travel. Ice on the steep upper slopes turns this into a technical objective and the runouts are unforgiving. Afternoon thunderstorms build reliably over these peaks in July and August, and the exposed ridge is precisely where you do not want to be — be heading down by early afternoon. There is no reliable water above Icehouse Canyon, and the creek there requires treatment. Carry at least three liters and more on a warm day.
Hiking tips for Telegraph Peak
- Start at dawn; thirteen miles with 4,700 feet of gain at altitude takes most people far longer than their flatland pace predicts.
- Account for the undulating ridge, where you lose and regain elevation and end up climbing the same ground more than once.
- Treat turning around at Timber Mountain or Icehouse Saddle as a good day, not a failure — the ridge punishes people who push late.
- Pack a wind layer regardless of trailhead conditions; the summit is exposed and windy far more often than not.
- Be descending by early afternoon in summer, when thunderstorms build fast and the exposed ridge offers nowhere to shelter.
Nearby trails to explore
- Timber Mountain
- Icehouse Canyon
- Ontario Peak
Hike this trail with TrailMates
Telegraph Peak is a genuine mountain day in the Cucamonga Wilderness. Use TrailMates to find experienced Inland Empire hikers running the Three Ts, share the permit logistics, and get an alpine start with people who will keep the pace. Download the TrailMates app.