Climbers Gathering

"Climbers Gathering" to be held Friday, Feb. 23 at Camp George West, Bldg. 48 in Golden from 5:30 - 10:00 PM. This informal event is open to the public and intended mostly for Colorado peakbaggers, whether it be 14ers, 13ers or other summits. Please RSVP to: [email protected]. Bring your own food and beverage.


LoJ: #62 (Pre-LiDAR #65) / 13,944' "Thunder Pyramid" Formerly UN 13,932

Range › Elks Range
Quadrangle › Maroon Bells
Summit Location › Peak Route Icon N 39° 03' 24.25", W 106° 57' 16.16" (Not Field Checked)

Peak Summary

We have sequenced Thunder Pyramid with Lightening Pyramid. The traverse between those two summits goes at a rough Class 3. Ice axe may be helpful for one or more sections. This climb is on typical Elk Mountains rock - friable, crumbly sandstone that breaks down into small scree and covers the ledges that have naturally formed from the sedimentary layers. Great care must be taken. This is not a climb for novices. The trailhead is accessible to any passenger vehicle, but during summer months, the hours you can drive up the Maroon Creek Road are restricted. We have included a backpack "approach" for those who want to plan more than one day to climb the three summits on the ridge south of Pyramid Peak.

Thunder Pyramid South Ridge Route

Class 3
Peak Icon Peak Icon
Medium Day // Take a Lunch
Climbed with "Lightening Pyramid"
RT From Maroon Lake TH: 11.2 mi / 4,660'
RT From 1st Creek Crossing with "Formerly UN 13,722 A": 3.7 mi / 3,780'
From "Formerly UN 13,722 A": 0.60 mi / 515' (One-Way)
  • Trailhead
    • Maroon Lake TH

      For quite a few years now, in order to regulate and reduce the vehicle traffic flow to Maroon Lake, the Forest Service has restricted vehicle traffic to Maroon Lake. Go to this link to search for detailed information:, but generally speaking, you can only drive a vehicle in before 9:00 AM or after 5:00 PM. Limited parking is available and can fill up rapidly on summer days. If arriving between 9:00 AM and 5:00 PM, you'll be required to ride a shuttle bus that runs every 20 minutes up to the lake.

      From State HWY 82 on the west side of Aspen, drive through the traffic circle south heading for the Aspen Highlands Ski area and Maroon Lake. This traffic circle is about 1 mile west of Aspen on HWY82 or 40 miles SE from Glenwood Springs, and after the airport and Aspen Business Center by the airport. The road number is CR13. The so-called "welcome station" is 4.7 miles south and that's where you must pay a vehicle use fee of $10. If attempting to drive in during restricted hours, you'll have to park at the Highlands Ski area and ride a free shuttle in. The trail to Crater Lake is what you need to locate at the SW end of the parking lot. The trail goes around Maroon Lake on the north and west side.


      Designated, fee campsites are available at the Silver Bar CG, the Silver Bell CG and the Silver Queen CG along CR13 as you drive in to Maroon Lake. These campgrounds are almost always occupied, especially on weekends. The White River National Forest website indicates that sites in these campgrounds can be reserved by calling 1-877-444-6777. There is no at-large camping allowed anywhere else along the road to Maroon Lake. Technically, vehicle camping in the parking lot at Maroon Lake is also off limits, but still practiced by many. Attempt at your own risk. The nearest other campground will be the Difficult Creek CG up HWY 82, about 4 miles east of town toward Independence Pass.

    Approach Map Photos
    • From Maroon Lake TH via 1st Creek Crossing & "Formerly UN 13,722 A":

      • West Maroon Creek  Easy | RT: 7.5 mi / 880’

        The "approach" begins at the Maroon-Crater Lake trailhead located on the east end of Maroon Lake. Watch for a registration station to obtain an overnight backpacking permit. Also plan on being required to have a bear-proof canister for food storage. The trail goes along the western shore of Maroon Lake amid the hordes of daily tourists. Many of these will make the hike to Crater Lake. This very-well-worn trail climbs steadily to Crater Lake passing the wilderness boundary (though you likely won't feel like you're in wilderness until you get beyond Crater Lake) along the way. It passes through a terminal moraine area before arriving at the lake and the trail comes to a junction near the lake on the northern end. The right fork leads up Minnehaha Creek to Buckskin Pass. For this approach however, you'll continue south on the trail that skirts the west side of Crater Lake and continues south to West Maroon Pass. There are designated campsites in the vicinity of Crater Lake.

        As you continue up the trail, there is an area not too far south of the lake where the trail gains about 100 vertical feet, then loses that elevation as it crosses an area of talus. The trail also cuts through numerous areas of willows, which when laden with rain drops and drooping over the trail, will provide a nuisance of a shower as you pack through. At about the 3.75 mile point, the trail crosses from the west to the east side of the creek. A little before that crossing, you may spot some suitable campsites that we used in 1993, on the same side of the creek as the trail. More sites exists after the creek crossing, about a half mile past at the most. Basically, you want to camp somewhere near where the access is to the somewhat hidden basin below Lightening Pyramid and UN13,631B. Camping here will make it possible to reach all three summits in a day as we did or will at least make getting all three summits in two days easily possible.

        Route shown is an approximation. Not intended for use as a GPX track.


        There are designated backcountry campsites at Crater Lake. Beyond there, as you proceed south up the creek, there will be other primitive site opportunities, if the White River National Forest is still allowing at-large camping. Check the most current regulations before making any assumptions. Over the last couple years, White River national Forest has moved in the direction of imposing a number of new camping and backpacking regulations on this area. The following coordinates are a "best guess" as to where we found a place to camp in 1993.

        Campsite Locations

        Creek Crossing Camp N 39° 03' 59.16", W 106° 58' 16.47"
        Elevation 10,500 ft.

        Open This Approach in a New Window
      • Lightning Pyramid West Couloir/Rib  Class 4 / 1.5 mi / 3,265’ One-Way

        Since we have included a backpack approach for these summits. the "route" begins from where the West Maroon Trail makes the first crossing from the west to the east side of the creek. When we climbed these summits in 1993, the winter of that year was a high snow year in the Colorado mountains. Those heavy snows persisted well into the summer, so our route decisions were influenced by those conditions. The three summits south of Pyramid were all climbed on the same day which was July 23, 1993. Most rate this a Class 3 climb on the assumption you stay mostly in the couloir. The difficulties we encountered staying out on the rock rib are what cause us to give this a Class 4 rating.

        From the vicinity of the suggested campsite, locate where the trail crosses to the east side of the creek and make the crossing however you can. There was no log bridge of any kind at the time we did this. On this occasion, there was a snow-bridge that made crossing easy. Once across, head east up through trees, working your way along by finding whatever trails you can - some game, some man-established. There are an alternating series of cliffs and benches with areas of trees. In 1993, we found a fairly direct, cairned trail that led us through a boulder field, then alongside a steep, snow-filled gully to another bench area. From there, the route into the upper basin at about 11,800 feet opens up rather naturally. By the time of this writing, we would expect there to be a well-used/marked trail.

        Once into this upper basin, take some time to oreint yourself and carefully identify each of the three summits - Thunder Pyramid, Lightning Pyramid and UN13,631B. You want to identify the correct couloir that ends up at a saddle between Thunder and Lightning Pyramid. Look for something you would not relish going up and that will likely be it. You should be almost directly west of the proper couloir. It empties onto a large talus field which rises about 400 feet in elevation to a cone that spreads out from the base of the couloir. The talus will then narrow into the couloir itself. In 1993, this couloir was filled with snow as far up as we could see. It was steep enough to leave us desiring crampons, which we did not have, but we did have ice axes. Several hundred feet up, the couloir passes through a particularly narrow section and appeared to even pass over some angled cliffs. G&M recommended avoiding the couloir in that section by following alongside on the exposed rock for a ways before re-entering. Because of the snow conditions, what we decided to do was to stay on the right-hand side of the couloir from the outset. We intended to remain on the rock rib until past the narrow section of couloir, then drop in at the first available spot. That never happened. If you find snow here, and it's early morning, it should be fairly firm for several hours before sun gets on it. We found the snow in the couloir to be hard and icy, which became yet another reason for staying out of it.

        Climbing on the rock rib on the right side of the couloir was somewhat exposed for much of the way. It consisted mostly of 3rd class scrambling on relatively stable rock with at least one point that required a minimum 4th class maneuver to get up across a rock band. Caution had to be maintained at all times. This was fairly continuous scrambling for nearly 1,200 vertical feet. It's easy to cut rocks loose and they will hurtle down with amazing speed. Helmets are highly advised. As you approach the summit ridge, the angle of ascent will moderate. By remaining on the rock rib and never entering the couloir, we came out just north of the summit by about 200 feet. The final scramble will be the easiest thing you've done for the last hour.

        From this summit, peruse the ridge in both directions, but mostly concentrate on reaching Thunder Pyramid to the north. If you were hoping for something easier than what you just did, you will be disappointed. Catch your breath and prepare to meet Thunder Pyramid. Our climbing partner for this day suggested that successfully navigating terrain like this may be more a matter of "dumb luck" than any actual skill we possess.

        Open This Route in a New Window
    Peak Icon Route Map Photos

    Route Info Thunder Pyramid South Ridge

    Route Description

    Year Climbed: 1993

    Thunder Pyramid is sequenced with Lightening Pyramid. One-way mileage and elevation gain are measured from the summit of Lightening Pyramid. Round-trip mileage and elevation gain assume completion of the sequence.

    Beginning from the summit of Lightening Pyramid, descend the ridge north to the saddle between the two summits. This saddle is at the head of the standard couloir used to ascend Lightening Pyramid. Generally speaking, there are no significant difficulties on this descent. The fun comes after the saddle. G&M recommended contouring from the saddle on the east side of the ridge and "picking your way to the first couloir that climbs back to the ridge crest." The couloir they refer to is quite obvious and can be seen in our provided photo. They go on to say that the "talus-filled couloir will bring you back to the ridge at 13,840 ft." This is all fine and good IF the couloir is free of snow. That is not how we found it on July 23. The recommended couloir was filled with snow in its upper reaches. It also had a near vertical cornice at the top. Having ice axes but not having crampons, a long ascent directly up the snow-filled couloir did not seem like a good idea. We ended up heading up the terraced slope on the east side of the ridge between the ridge and the couloir and aimed for a high and more narrow section of the couloir, crossing the snow to a rock"island" outcrop and then going on up to the ridge. This only required crossing the snow for about 30 feet before the rock island in the couloir and then a few more feet to exit and climb onto rocky ledges that took us back to the ridge crest.

    The remainder of the route to the summit simply follows the south ridge again with a few ridge steps that can be easily negotiated on one side or the other by searching for breaks in the low cliffs. Along this stretch you will pass the head of the "white rock" couloir that plunges off to the west side of the ridge. Make a mental note of it's location. The actual summit is about 100 yards farther. Breathe a sigh of relief for having arrived in one piece, but don't relax too much. A fairly hairy descent will be your reward for your efforts to reach this summit. The summit register as of last report dates back to August of 1970. Eddie Mack took photos of all the names in this register. We have posted Eddie's photos of the register as a pdf document in the photo gallery. The register reads as a "Who's Who list of Colorado's most well-known peakbaggers going back for almost five decades. This should be considered an historical document!

    After absorbing the amazing view and regathering your nerves, it's time to descend. Head back south down the ridge crest to the white rock couloir mentioned earlier. In 1993, we were able to descend the first few hundred feet on loose, rubbly rock and scree. This gave way to snow. Here is where toting an ice axe for this climb may come in handy. The snow affords a quick descent of over 1,000 feet. If the snow is hard and icy, you may not want to glissade down. Exercise good judgment here. Once below the snow, follow low ridges and gullies heading more and more south and west to get back into the basin at 11,800 to intersect your ascent route from West Maroon Creek. G&M recommended "turning left at 12,000 feet above a cliff band and traversing left to easier, grassy slopes." The last few hundred feet of descent back to the basin will be mostly on loose talus. This upper, partially hidden basin has a very private feeling to it. On the west side of the creek, it's mostly gentle tundra until it ends abruptly against the savage gray-maroon cliffs darkened by runoff and snow-melt from above. On the east side of the creek in this basin, it's almost all talus. If you have arrived back here early enough in the day and the weather is not threatening, you may want to consider doing as we did and going ahead to climb UN13,631B. This was not planned on our part, but when the opportunity presented itself, we grabbed it.

    Additional BETA

    Links to other information, routes & trip reports for this peak that may be helpful.
" I think most of us who are climbres recognize that we have a need for some sort of battle as part of our lives. I use to like getting up in the mountains and hiking around, but I knew I wanted something more exciting." Royal Robbins Yosemite climber
Warning! Climbing peaks can be dangerous! By using this site and the information contained herein, you're agreeing to use common sense, good judgement, and to not hold us liable nor sue us for any reason. Legal Notice & Terms of Use.
Donate to ›