Diamond Peak
Diamond Peak rises to 12,197 feet and is the highest summit in Idaho’s Lemhi Range as well as the tallest mountain in the state outside of the Lost River Range. True to its name, the mountain rises like a pyramid above the surrounding valleys and is one of only three ultra-prominent peaks in Idaho. The standard route follows the East Ridge and offers a long, scenic scramble with plenty of Class 3 terrain. While the first half of the hike is relatively straightforward, the upper ridge becomes more complex and demands careful route-finding. This Diamond Peak hiking guide covers the route, difficulty, key hazards, and what to expect on one of Idaho’s best scrambling peaks.
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Watch the full Diamond Peak hike in the video below:
Route Overview
The standard route follows the East Ridge. The first portion is straightforward before transitioning into a long scramble along the ridge. Staying near the crest generally provides the most stable terrain, while side paths can lead into looser rock. The upper mountain becomes more complex, with multiple route options and increasing exposure.
How Hard is Diamond Peak?
Diamond Peak is rated Class 3, though it can feel more difficult depending on route choices. Staying on a solid line keeps the difficulty manageable, but drifting off route can quickly lead into looser or more exposed terrain. It is best suited for hikers comfortable with scrambling and basic route-finding.
What Makes the East Ridge Tricky?
The challenge of Diamond Peak is not a single crux, but the sustained nature of the ridge. It is a far longer and far crumblier climb than Chicken Out Ridge over on Borah Peak. Scrambling begins earlier than expected, and multiple use paths can pull hikers away from the best line. WHen in doubt, stay slighlty right to avoid a large cliff. The ridge itself typically offers the most secure travel, while side routes can increase difficulty.
Best Time to Hike
Diamond Peak is most commonly climbed between July and October. In dry summer conditions, the route is a straightforward scramble. Earlier in the season, lingering snow can increase difficulty and require additional skills and equipment.
Tips, Gear, and Common Mistakes
There is no water on the route, so plan accordingly. An early start helps avoid heat and weather risks. The most common mistake is underestimating route-finding on the upper ridge. Staying near the ridge crest usually provides the safest and most efficient line. Also, the trailhead can be diffiuclt to get to due to the dirt roads. Be sure to bring a high clearance vehicle.
Should You Hike Diamond Peak?
Diamond Peak is one of Idaho’s best scrambling peaks for hikers comfortable with off-trail travel and Class 3 terrain. Those new to scrambling may find the upper ridge more challenging than expected. With experience, it becomes a highly rewarding climb.
Looking for your next Idaho 12er? Diamond Peak is one of the most enjoyable scrambles in the state. My guidebook covers all of Idaho’s 12ers, with detailed routes, maps, and tips to help you confidently take on peaks like this and beyond.
