The Roof of Idaho’s Sawtooths: Hiking Thompson Peak

By Michael Lanza

Morning fog hung like a damp, cold blanket over the Sawtooth Valley as my wife, Penny, and I started hiking in early morning from the Redfish Trailhead, minutes from the shores of Redfish Lake. Before long, we caught our first view of our destination—and it looked quite far off: the pinpoint summit of 10,751-foot Thompson Peak, the highest in Idaho’s best-known mountain range, the Sawtooths.

From where we started our dayhike, 6.5 circuitous miles and 4,200 vertical feet separated us from that lofty piece of granite, including on- and off-trail hiking through aspen and ponderosa pine forest, up a hanging valley with a steep headwall, over a stretch of talus and scree, and a bit of third-class scrambling.

But Penny had never stood atop Thompson, and we had a bluebird, late-July day. We fully intended to get there.

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Thompson Peak towers prominently above the Sawtooth Valley at the eastern front of the Sawtooth Range, where a row of jagged peaks and spires extends for miles. Looking up at them reminds me of the view of the Tetons from Jackson Hole (although the Sawtooths do not match the relief or heights of the Tetons). I’ve hiked and backpacked all over America for about four decades, including many years as Northwest Editor of Backpacker magazine and running this blog, and from my perspective, Thompson Peak stands out as a great hike with five-star scenery much of the way, challenging terrain that’s feasible for many fit hikers, and a spectacular summit

According to Idaho—A Climbing Guide, by Tom Lopez, 33 summits in Idaho’s Sawtooth Mountains exceed 10,000 feet. That total depends on which ones you count. Using that guidebook, I’ve put together a list of 37 Sawtooth peaks over 10,000 feet that look worthy of climbing, although some may be considered just subsidiary summits of another mountain.

Click here now for my expert e-guide to the best backpacking trip in Idaho’s Sawtooth Mountains!

The top of Thompson lies just close enough to the nearest trailhead to reach in a day, and just far enough away to make that a pretty full, rigorous day. But it’s a day filled with much of what we head into the mountains for: challenge, inspiring scenery, deep quiet, perhaps a frigid dip in an alpine lake, and a surprising degree of solitude for the highest peak in a well-known mountain range.

Penny and I broke out above treeline while the fog still filled the valley below us, but it burned off quickly. A little while later, we passed the alpine lake that sits in a stone bowl at 9,000 feet—a lake unnamed on maps but often called Goat Lake by locals—below the dramatic spires of Thompson’s east ridge. Farther still, small, shallow tarns reflected those spires. I looked around at the magnificent cirque framed by Thompson Peak and its neighbor, Williams Peak, a fine destination for a hike even if you have no intention of attempting one of these summits.

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A hiker on her way up Thompson Peak, the highest in Idaho's Sawtooth Mountains.
My wife, Penny, hiking Thompson Peak (the summit in upper right of photo), the highest in Idaho’s Sawtooth Mountains.

Four-and-a-half hours after starting out, Penny and I scrambled about 15 feet of steep, blocky rock onto the sloping tabletop that comprises Thompson’s summit. The breathtaking view took in Goat Lake 1,700 feet below us; most of the Sawtooths to the east and south; the shimmering Salmon River in the Sawtooth Valley and another great Idaho mountain range, the White Clouds, to the east; and the rumpled blanket of peaks and canyons of the Frank Church-River of No Return Wilderness to the north.

There was hardly a breath of wind, the sun beat down warmly, and we had the roof of the Sawtooth Mountains to ourselves on that July weekday.

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Thompson Peak is a great mountain climb. It’s shockingly scenic just about every step of the way. It’s varied and challenging, long and tough: Afterward, Penny, who has climbed a lot of mountains, was surprised at how strenuous it was. It’s ambitious and rewarding.

See my stories “The Best Hikes and Backpacking Trips in Idaho’s Sawtooths” for a description of the standard hiking route to the summit of Thompson as well as other great dayhikes and backpacking trips in Idaho’s premier mountain range, and “The Best of Idaho’s Sawtooths: Backpacking Redfish to Pettit.” and all of my stories about Idaho’s Sawtooth Mountains.

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The Best of Idaho’s Sawtooths: Backpacking Redfish to Pettit

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14 thoughts on “The Roof of Idaho’s Sawtooths: Hiking Thompson Peak”

  1. hey Michael, those are some awe-inspiring photos. I will be staying at Redfish Lake in a month. Is this trail doable at the beginning of June? or too much snowpack?

    • Hi Tom,

      No, in early June you will encounter solid snow cover probably not far beyond the trailhead near Redfish Lake. You’ll be able to see how much snow remains in the mountains from the lake, where there may even still be snow. The only way to climb Thompson or other peaks in spring is on skis or snowshoes, with a full belly of endurance for a very hard day and expertise in evaluating avalanche hazard.

  2. Great little article. As I sit in my “office in the city” I daydream of the places I have been and the places I will go. You have helped me and for this I say thank you.

    Todd – Santa Rosa, CA

  3. Michael,
    Your website is great – I especially loved your writeup of your favorite backpacking trips. I just did Cirque of the Towers last weekend. What an incredible place…

    I’ll be driving via the Sawtooths this weekend and am intrigued by Thompson peak. I am a seasoned hiker but not a climber. Would this be something feasible to do solo?

    Thanks for your help!

    • Thanks for the kind words, Christoph, I’m glad you find my blog enjoyable and helpful.

      Yes, plenty of experienced hikers with good off-trail navigation skills and comfort with a little, relatively easy scrambling and a bit of exposure hike Thompson solo; I’ve done it solo and several times with companions. Great hike, as the photos probably demonstrate.

      The route-finding can be a little tricky. It’s not obvious without some description of the route but not hard if you go there with some information. If you’d like my help with that, check out my Custom Trip Planning page to learn how I operate that. If you’re only looking for details on that one hike, I would negotiate a fair price with you.

      I hope you sign up for my free email newsletter and decide to Join The Big Outside to get full access to all of my blog’s stories.

      Good luck. Please keep in touch!

  4. Hi Michael,

    Do you recommend any special gear to complete this hike? (micro-spikes, ice axes, hiking poles, etc.)

    Thank you!

    • Hi Anna,

      From late July through September and usually even later in fall, you won’t need any special gear like an ice axe or crampons. I always hike with poles, for several reasons, and they are particularly useful on rugged, off-trail hikes like Thompson Peak, so I’d certainly recommend taking those.

      See my picks for “The Best Trekking Poles.”

      Thanks for the good question.


  5. I’ll be heading out to attempt this from another direction over Labor Day. I’ll be coming up the drainage on the other side of Williams and Thompson. Would you recommend finding the saddle between the two, where you came up from the other side and then approach the summit from there, or is it easier to summit from the southwest?


    • Hi Mitch, I think you’re talking about the drainage accessed from Goat Lake (below Merritt Peak) and hiking up it on the west (back) side of Williams Peak to gain the Thompson-Williams saddle. I’ve done that, it’s fairly straightforward, though there’s a steep (a bit of 3rd class) headwall to reach the saddle. Then you just gain the standard route up Thompson from the saddle. Yes, hike around to the southwest side of Thompson and follow a climbers trail to the summit. If you turn for the summit before reaching the southwest side, you’ll run into cliffs. Good luck. It’s an awesome hike.

  6. Hi, I was wondering if 4th of July weekend would be too early for this peak, or even for general backpacking in the Sawtooths? Thanks so much!

    • Hi Shawna, thanks for the good question. Yes, 4th of July weekend would be early most years, and this year wouldn’t be any different. I would expect to run into solid snow cover above roughly 8,000 feet, and the summit of Thompson is at nearly 11,000 feet. The steep headwall you have to get over on the hike, between Thompson and Williams peaks, would be technically difficult and possibly dangerous with a lot of snow on it. Plus, there’s a lot of off-trail walking on rugged terrain, including talus boulders where if you broke through a snow bridge, you’d fall between large rocks. It’s best to wait at least until mid-July. Good luck.

  7. I was always told that Thompson Peak was beautiful, but your pictures make it true. I have cousins that live in Idaho and are always telling me to go camping to see their state’s beauty. Now it is a must the next time I visit idaho. Loved your blog.