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The Elk Range's easiest 14ers provide a challenge for runners and skiers alike.

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14,010' 4,270 m


9,852' 3,003 m


4,299' 1,310 m


4,298' 1,310 m



Avg Grade (8°)


Max Grade (24°)

Dogs Leashed

Features River/Creek · Views · Waterfall · Wildflowers · Wildlife

With a good 4WD vehicle (Jeep, FJ, Xterra, etc.) a competent driver can make it almost all the way to the start of the Castle Peak trail. Most people will have to park much further down, however, especially during the spring and early summer. During the winter, the road is closed just beyond the lowest point mapped.

The land manager requests dogs be leashed. While a good mountain dog can do this run, it's a long day full of loose, rocky terrain. Seriously consider this before bringing a dog.


Nestled to the east of the Elk Range's more famous (albeit shorter) 14ers, Castle and Conundrum still offer plenty of recreation on their own. The standard routes described here take runners over classic Elk Range terrain: steep, loose rock...and lots of it. These mountains push the limits of your feet because if they were any harder, you'd be scrambling on all fours.

Conundrum Couloir (Snow Route) is also worth mentioning: snow climbers and skiers alike should consider adding it into the linkup for an even more ambitious day.

Need to Know

While the easiest Elk 14ers by far, the range is home to some of the most deadly peaks in the state (North Maroon Peak, South Maroon Peak, Capitol Peak, Pyramid Peak). Don't take these mountains lightly. Bring all the usual essentials and be prepared for an 8-12 hr day.

Runner Notes

The road up to Castle Peak trail is certainly runnable, but just as certainly uninspiring. Once above 12,000 ft or so, the trail is generally either too rocky or steep for serious running. It's not undoable, but there are plenty of better options in the area.


From the roundabout just west of Aspen proper, take Castle Creek. Drive 12.5 miles to the Castle Creek Trailhead, turning right onto Forest Road 102. From here, the road is dirt and undrivable for most cars. Even 2WD vehicles can make it about half a mile to camp along the creek. A true 4WD vehicle (Jeep, FJ, Xterra, etc.) can continue 2.2 miles from the pavement, bearing right at the junction with Pearl Pass, and making it all the way to 12,000ft at the upper trailhead. This, of course, is all dependent on road conditions and snow.

From the lower trailhead, run on a clear dirt road. Ascend gradually through a brief bit of forest before switchbacking right and then left. Stay parallel to Castle Creek. There will be cars parked at various points along the road. After 2.2 miles, come to a junction with the Pearl Pass road. Turn right and cross a bridge, continuing up a rocky road (FR 102, poorly marked).

Run 2 miles up the road through talus fields and forest patches. In the spring there is generally some avalanche damage to trees in this area, so don't be too surprised if there are some downed ones along the trail. Follow the road into Montezuma Basin, reaching the abandoned Montezuma Mine at 12,400ft. The road ends at 12,800ft, as the basin begins to open up.

From here, follow a poorly marked and difficult, rocky trail to the left. Your goal is to run up to Castle Peak's northeast ridge. Don't fret too much if you can't find the trail. Aim for the saddle in the ridge and you'll be fine. Run up steep talus to 13,400ft, at which point the ridge is mellow. Continue up 300 more ft along the right side of the ridge before reaching the ridge proper (13,700ft). Things become more difficult from here. From here, the grade is very steep and the rock very loose. It doesn't quite require scrambling, but it's close. Fortunately the trail here is a little clearer, at least for a little bit, so you can't get too off route.

Run/scramble up the remaining 500 vertical ft of loose, steep rock. The summit is visible from about 14,000ft, so don't get too amped up for the false one. After the false summit, drop just a bit to a small saddle. The summit's less than 300ft up. Push on.

From the summit of Castle Peak, it's under a mile to Conundrum, visible right across Montezuma Basin. Of the two apparent summits, the one to the right (north of Conundrum Couloir (Snow Route)) is the true summit. Descend northwest down loose rock to the Castle-Conundrum Saddle at 13,800 ft. While the trail here is rocky and hard to follow, it becomes easier on the ascent up Conundrum. Run up steep, rocky trails similar to but easier than the ridge to Castle Peak. Expect this bit to be absurdly steep. It's probably easier with snow present.The trail will flatten as you approach the false summit. From here, dip down a notch toward Conundrum Couloir (Snow Route) before climbing up another 50ft or so to attain the real summit.

Adventurous types may opt to ski or glissade down Conundrum Couloir (Snow Route) while true gluttons for punishment will just do the route in reverse. Either way, it's a hell of a day.

Flora & Fauna

You'll see marmots, pika, and possibly some bighorn sheep and mountain goats. The Elks are home to many-a-bear, although there aren't many reports of them here. When I did this run I was stalled on the trail by some early morning coyotes. careful!

History & Background

Castle Peak's name is derived from the summit's "castellated appearance." It looms over a quasi-permanent snowfield, rendering these peaks a destination for Colorado's backcountry skiers and snow climbers.


Shared By:

Tyler Prince

Trail Ratings

  4.7 from 12 votes


  4.7 from 12 votes
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5 Views Last Month
6,323 Since Mar 19, 2015
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Looking back at Castle peak from the ridge to Conundrum.
Feb 25, 2024 near Aspen, CO
Making the hike back over the saddle from Conundrum.
Feb 25, 2024 near Aspen, CO
On the ridge for a smoky sunrise.
Feb 25, 2024 near Aspen, CO
Bridge debris - watch your step!
Mar 25, 2015 near Aspen, CO
Looking up the rugged terrain
Mar 25, 2015 near Aspen, CO
View from the summit of Castle Peak. To the left is the saddle to which you'll descend. Conundrum is right in front of you, with its technical couloir just right of center. Conundrum's summit is up and to the right of the couloir.
Mar 20, 2015 near Aspen, CO



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