• Jagged Mountain

The 6 Best & Hardest Mountains to Climb in Colorado

Colorado has 1,313 raked mountains which rise over 12,000 feet. Compared to almost anywhere else in the world, this represents an astonishing amount of high-mountain terrain. While the absolute height of the mountains in Colorado may not rise as high as other great ranges of the world, the sheer diversity, variety, and access to high peaks is almost unrivaled.

The volume creates an incredible playground for outdoor enthusiasts. Regardless of how you like to enjoy the mountains, there is guaranteed to be something for you in Colorado.

For backpackers, there are thousands of trails, lakes, and valleys to explore.

For rock climbers, Colorado has some of the best alpine walls in America.

For backcountry skiers, the number of lines to ski down is virtually endless.

For trail runners, some of the toughest (and most prestigious) outdoor races in the world cross the state.

And for peak baggers, there are enough easy trials up gentle mountains to stay occupied for a lifetime.

But all of this got us thinking: out of all these mountains, what are the gnarliest peaks out there? For those looking to push the outer limits of mountaineering, where can they find the best of the best in Colorado? Where do climbers and mountaineers cross into the realm of true expert terrain?

With those questions in mind, we decided to compile our list of the 6 gnarliest mountains in Colorado, as well as details for how to climb each. Some can be done by experienced climbers, and some require years of technical training before a summit can be attempted.

Regardless, if you ever find yourself atop one of these summits, the experience will almost certainly change you for life.

What makes a mountain Gnarly?

Ranking mountains in terms of ‘hardest’ or ‘toughest’ raises all kinds of questions. There are plenty of different ways to measure the challenge of attaining a summit. Climbers love to compare notes and debate these things and every list is pretty much guaranteed to contain a healthy amount of subject evaluation.

For the purposes of our list, we’ve tried to consider a wide mix of factors. Some of the chief among them are: route length & distance, aesthetics, approach, technical difficulty, risk, exposure, and abundance / types of routes. Undoubtedly there will be a ton variance from one climber to another, but we simply tried to take a good general review of Colorado’s high peaks to come up with a serviceable top six.

  • #6 – Longs Peak (14,255’)

Longs Peak 1

Longs Peak’s famous east face, as seen from Chasm Lake. A mountaineer’s dream.

Our list begins with what is perhaps the most iconic mountain in the state.

Longs Peak is the monarch of Rocky Mountain National Park. It towers over the surrounding mountains and acts as a perfect sentinel for northern Colorado. Indeed, it is one of the most prominent mountains in the entire state, rising some 9,800 vertical feet above the eastern plains just a few miles away.  Its history and terrain are legendary.

Longs fits the definition of ‘gnarly’ by just about any standard. It is a mountain that is as fierce as it is tall, and as dangerous as it is epic. The entire massif is filled with soaring cliff faces, sharp towers, steep drop-offs, and challenging terrain. There are no gentle or easy approaches to the mountain and it often can feel more like a fortress instead of a peak. Longs has captured the inspiration and dreams of thousands of photographers, artists, locals, and visitors over the years. Its aesthetic beauty is hard to beat.   

No matter how you approach Longs, climbers are faced with unique and interesting mountaineering challenges. There is an unbelieveable amount of technical and advanced terrain contained in such a small area. In fact, Longs has over 100 named routes to its summit. All but a very small percentage require some degree of technical, roped climbing.

All of these factors make Longs a very worthy opener to our list. This cirque is quite possibly the finest in the lower 48.

How to Climb It:

  • Long Peak 2

    A climber prepares to cross The Narrows on Longs.

    Easiest Route: The Keyhole Route

  • Difficulty: Class 3
  • Round Trip Distance: 14.50 Miles
  • Vertical Gain: 5,100 feet

For those looking to scale Longs, thankfully there is a class 3 route to the top. The Keyhole Route circumnavigates nearly the entire peak as it winds its way upwards to the summit. It is a stunning introduction to the mountain.

But this is a long, challenging day with a ton of vertical gain. It will stretch the capabilities of most hikers to their absolute limits and is certainly no place for those who are sketched out by heights. Nevertheless, this route is, by far, the most ascended of our list as many climbers attempt it each summer. A few highlights along the way include:

  • The Boulderfield – An expansive field of huge rocks perched beneath the imposing North Face.
  • The Ledges – A slippery, steep set of traversing ledges.
  • The Trough – A loose gully with rock fall presenting a danger
  • The Narrows – A hair-raising, single file traverse above 200-foot cliffs.
  • The Home Stretch – A rock scramble up the steep final face to finally reach the football-field-sized summit.   

Bonus Gnarliest Route: The Diamond

Longs Peak’s east face is a vertical wall rising some 2,000 feet above Chasm lake below. The upper portion, named ‘The Diamond’, is a world class climbing spot. Alpine rock climbing at 14,000 feet will push even the most experienced rock climbers to their absolute limits.

Long Peak 3

The Diamond is a sheer, slightly overhanging 1,000 ft wall comparable to any other world class alpine wall. Nearly a hundred named rock routes ascend to its summit.

  • #5 – The Maroon Bells (14,156’)

Maroon Bells 1

The view of the Maroon Bells from Maroon lake is easily the most photographed spot in all of Colorado. And it is with good reason. These twin peaks (North & South Maroon) rise in dramatic fashion above the water. Their steep faces and maroon rock provide the perfect backdrop against the green grass and yellow aspens below. One glance up at these towering peaks from the shores of the lake is enough to understand what makes them so gnarly.

But a closer look reveals an even more sinister trait about the Bells: they are loose. Very loose. In fact, these mountains might contain some of the most dangerous, hair raising rock of anywhere in Colorado. “Red, loose, and rotten” as the old adage about them goes. The aging mudstone feels the full effects of erosion as it has created a series of very thin and weak bonds holding the rock together. When this is combined with the steepness found on all sides of these pyramidal peaks, the result is high danger.

In fact, a sign along the approach trail warns climbers of these hazards and highlights the nick-name for these two: ‘The Deadly Bells’.   

When all of this is combined with the dramatic rise from the valley below, you get easily two of the toughest 14ers in Colorado.

How to Climb It:

The easiest way to ring one of the bells is to ascend Maroon Peak via its South Ridge. After a gentle start up the valley, the route quickly turns into a calf-destroying slog up a steep, 3,000 foot grassy slope. This one will test the limits of any cardio program. From there, the true climbing begins as you must do an ascending traverse across a series of cliff bands, steep faces, and horrendously loose rock gullies.

Maroon Bells 2

The various approaches and routes up the Maroon Bells can be seen in full view from neighboring 14er, Pyramid Peak.

Bonus Gnarliest Route: The Bells Traverse

For those wanting to reach both summits, the peaks can be linked via The Bells Traverse – a complicated, loose, and challenging traverse along the connecting ridge between the two summits. Depending on the direction chosen, this may require a mandatory rappel and / or roped rock climbing for portions of the route. All the while, huge exposure and tremendous faces abound. This may be the most dangerous connecting ridge of any two peaks in the state.

Maroon Bells 3

Climbers working their way across the Bells Traverse. Steep and loose rocks are the rule here.

  • #4 – Capitol Peak (14,131’)

Capitol Peak 1

The final 14er on our list is a neighbor of the Bells. Capitol Peak is another mountain in the Elk Range of Colorado, just a few miles away from Maron & North Maroon Peaks. But while those two summits are quite happy to be the most famous duo in the state, Capitol is easily the King of the Elks.

Capitol is massive, imposing, and rugged. The mountain is a long, narrow hulk of rock with sweeping drop offs on both sides. 2,000+ foot cliff faces are continuous across the length of the peak. Interspersed amongst the faces are a series of yet more loose and rotten rock bands. The occasional couloir or steep gulley penetrates the cliffs as well and daring climbers can poke their heads over the edge to peer into Pierre Lake Basin thousands of feet below.

All of this adds up to a massive hunk of rock which could very well be the most impressive single mountain hulk in Colorado. Sitting at Capitol Lake and peering up at Capitol’s north face is an experience few will forget. The sheer scale, size and beauty of nature will hit you as you look up at some of the prettiest and most impressive cliff faces to be found anywhere.

How to Climb It:

Capitol’s reputation amongst Colorado peakbaggers is notorious. It is generally regarded as the most challenging and difficult 14er summit to reach and with good reason. The entire day is a grueling 17 miles and 5,300 vertical feet of gain. As such, most parties choose to camp at Capitol Lake the night beforehand to break up the route.

From the lake, climbers ascend a frighteningly loose pass to gain the upper ridge. This section contains the most feared portion of the route: The Knife Edge. This 100 foot section requires a traverse across a razor sharp points of rock with 1,000 foot drops on either side. The exposure can be mind-boggling. Past the knife-edge, a final sequence of tricky class 4 gullies guard the final moves to the summit.

For those who make it this far, this remote summit makes for a fitting and worthy end to those looking to finish their 14er list in Colorado.

Capitol Peak 2

Climbers carefully navigating their way across Capitol’s knife edge. Any mistakes here result in a one-way trip.

Bonus Route: Ski Descent

Capitol is the most challenging 14er to climb and it is also the most challenging to ski. The difficulties in skiing the peak are next-level. Those wishing to descend on planks will encounter mandatory 55-60 degree slopes, severe avalanche danger, and turns being made over a constant series of 1,000 foot cliffs. The entire route is a massive no-fall zone on some of the most challenging ski terrain of anywhere on earth. It is the crux of the ski the 14ers project and a world class line by just about any standard.

  • #3 – Lizard Head (13,113’)

Lizard Head 1

Lizard Head seen in early spring, dominating its surroundings.

We now turn our attention to the 13ers of Colorado. While these peaks do not rise quite as high as their bigger brothers, they certainly make up for it in gnarliness. Our first is Lizard Head.

Lizard Head might be the most striking peak in all of Colorado. When most of us think about mountains, we think of massive hulks of rock and ascending upwards into the heavens. Rarely do we think of sharp, skyscraper-esque towers that rise straight up into the sky. But that is precisely what Lizard Head is.

This spire of rock is an incredibly unique mountain. What starts as a relatively tame mound ends in dramatic fashion. The final 500 feet of this ‘peak’ is a volcanic pinnacle that juts up out of seemingly nowhere. On all sides the spire rises to vertical and is capped off with a strikingly sharp final summit.

This tower of rock looks like it might be better suited for a Lord of the Rings movie than a test piece in the Colorado wilderness, but thankfully for us, we get to admire its beauty from up close and personal.

How to Climb It:

  • Easiest Route: Southwest Chimney
  • Difficulty: 5.8+ (YDS)
  • Round Trip Distance: 7 miles
  • Vertical Gain: 2,500 feet

Lizard Head Peak may be the single hardest summit to attain in all of Colorado. Reaching the top requires roped climbing on very challenging terrain. The three pich route goes at 5.8 on the Yosemite Decimal Scale and is for very experienced climbers only.

But the real crux of the problem isn’t necessarily the difficulty of climbing, but the horrible, loose rock on which it must be done. Lizard Head is notorious for being very rotten, and therefore dangerous, for anyone attempting to scale the peak. This also makes the route very difficult to protect adequately, further complicating an ascent.

Nevertheless, Lizard Head is a ranked 13er, and therefore, it is usually the crux of the project for those seeking to climb all 676 13ers in Colorado. For weekend warriors and seasoned rock climbers, it is an equally valuable prize.

Bonus Route: First Ascent.

Lizard Head’s difficulty is such that there really isn’t a way to make it any spicier than it already is. It is challenging enough on its own.

However, the peak is undoubtedly easier now (thanks to rock trundling) than when it was first ascended by legendary Colorado mountaineer Albert Ellingwood. Here is what he had to say after the first ascent of the spire:

“A rottener mass of rock is inconceivable. The core may still be solid but the “surrounding tuffs” are seeking a lower level in large quantities. This far-advanced disintegration was our greatest obstacle. Absolutely the whole surface of the rock is loose and pebbles rain down from the sides as readily as needles from an aging Christmas tree. In many places one could with one hand pull down hundreds of pounds of fragments, and occasionally we could hear the crashing of small avalanches that fell without human prompting.”

  • #2 – Peak Fifteen (13,700’)

Peak fifteen 1

Peak Fifteen (left), sits amongst some of the gnarliest and least accessible terrain in the Rockies.

Peak Fifteen lies in the middle of the Weminuche Wilderness – the finest wilderness area in all of Colorado, and perhaps, the continental US. This remote area encompasses a huge landmass which contains most of Colorado’s finest and gnarliest peaks. Remote and rugged, those who climb here find a special affinity for the beauty and challenge of these mountains.

There are hundreds of challenging summits to choose from in the Weminuche, but Peak Fifteen stands out for its position and unavoidable difficulties. Yet again, we’ve found ourselves on a mountain requiring mandatory rock climbing up steep, exposed, and dramatic faces. Peak Fifteen sits amongst a dizzying labyrinth of rock spires and towers, and very careful navigation is required to navigate to the summit. The only way to reach the top is via a sequence of roped pitches which follow a series of narrow gullies over exposed cliff faces.

But the summit is sublime. Climbers who reach this summit find themselves in the heart of the San Juan Range – the finest in all of the Rockies. The reward is well worth the effort.

How to Climb It:

  • Easiest Route: Southeast Face
  • Difficulty: 5.0 – 5.2
  • Round Trip Distance: 16+ Miles
  • Vertical Gain: 6,000 feet

What really sets Peak Fifteen peak apart is the effort required just to reach the base. The only accessible approaches for the Peak require 16+ miles of backpacking through some of Colorado’s most remote terrain. A 2-3 night backpack into Ruby Basin is required just to get back here and access the routes. There are a few different options to reach the upper drainage, and each has its pros and cons. However, the effort is sure to pay off.

Once a high camp is established, climbers must climb a steep, often-icy north facing couloir to wrap around to the back side of the mountain. A series of harrowing traverses awaits before finally reaching the bottom of a multi-pitched final effort to reach the top. Time to rope up as the final pitches go anywhere from 5.0 – 5.2 depending on the exact route. But that is what makes this peak so great – it is one of the elites in Colorado requiring a mandatory rock climb to reach its summit.

Peak Fifteen 2

Climbers on belay as they prepare to scale the final portions of Peak Fifteen.

Bonus Gnarliest Route: Pigeon & Turret

Peak Fifteen sits right next door to two of Colorado’s most dramatic 13ers: Pigeon and Turret. These ‘Centennial 13ers’ are two of the highest 100 summits in Colorado. While slightly less technically challenging than Peak Fifteen, they are no less incredible and aesthetic. Given all the effort just to reach the remote Ruby Basin, a side trip to summit Pigeon and Turret will usually be in the cards for most parties.

Peak Fifteen

Peak Fifteen, Pigeon, and Turret make for one of the best outings of anywhere in Colorado.

  • #1- Jagged Mountain (13,824’)

Jagged Mountain

Jagged Mountain is Jagged – extremely, unbelievably so. Unlike any other mountain in Colorado, Jagged’s aesthetics and climbing challenges are unrivaled. It is a fitting candidate to top our list of the gnarliest mountains in the state.

Nestled in the heart of the Weminuche Wilderness, Jagged Mountain has features that no other peak can rival. Its sweeping summit ridge is a dizzying array of towers, spires, and blocky knobs. Its faces on all sides are a sequence of frightening cliff bands. Its rock is loose and dangerous. And its ledges contain thin strips of slippery grass which make climbing it a challenge. Just looking at the mountain can give even the most seasoned mountaineers pause.  

The beauty and wonder of Jagged is reserve for those who are willing to make the effort. It cannot be seen from any road and a multi-day trip is required to enjoy its views and awesome faces. It might be the premier 13er in all of Colorado, if not the finest mountain in the whole state.

How to Climb It:

  • Easiest Route: North Face
  • Difficulty: 5.2 (YDS)
  • Round Trip Distance: Varies by approach, but anywhere from 19-31 miles.
  • Vertical Gain: 6,000+ feet.

Like Peak Fifteen, Jagged requires a multi-day backpacking expedition to reach its lower flanks. There are multiple ways to get into No Name Creek, the basin in which Jagged lies, and each is filled with its own adventures. Regardless of the chosen approach, the remoteness and difficult access only adds to the allure.

To climb Jagged requires a series of complex and well-thought out route finding moves on its sweeping North Face. To even identify the correct summit is a challenge in and of itself, let alone to climb it. Such are the complexities of a mountain with hundreds of spires and confusing rock bands.

The basic route ascents a series of frightening, steep gullies with slippery rock interspersed throughout. Identifying the correct passages is paramount to eventually reaching the correct rock ribs above. A sequence of ribs must then be climbed, before reaching the final chimneys to reach the summit. The rock climbing here reaches 5.2 and a rope is mandatory for almost all parties.

Jagged Mountain 2

Steep rocks, cliffs, and grassy ledges are the rule on jagged.

However, the good news (or bad depending on the climber) is that the face is too complicated and steep to downclimb. So, a rappel off the summit is the usually chosen method of descent instead. Dangling from a rope off of Jagged’s summit with the entire expanse of the Weminuche at you feet is as sublime of an experience in Colorado as you can get.   

Bonus Gnarliest Route: Do it in winter

Given its climbing challenges, Jagged boasted one of the final first ascent opportunities remaining in Colorado. Up until 2016, no climbers had ever reached Jagged’s summit in winter. Given the distances, complexities, and dangers involved in such a climb, it’s little wonder this accomplishment was incomplete for so long.

However, in 2016 a pair of daring climbers finally made the first calendar winter ascent of the peak. You can read about their adventure here. And so, anyone wishing to make this climb even more of a challenge, the second known winter ascent awaits you!  

About the Author:

David Yarian grew up exploring and playing in the mountains of Colorado. He has climbed all 58 14ers in the state, to go along with hundreds of other summits throughout Colorado and abroad. He is thankful for every safe and fun outing in the hills. You can read all about his climbing, skiing, hiking, and trail running exploits on his blog, Exploring the Rockies.


Climbing mountains is an inherently dangerous activity. It requires sound judgment, honed experience, and adequate physical conditioning. The peaks mentioned above represent some of the most challenging, difficult, and dangerous climbing in all of Colorado. The information and descriptions in this post is in no way meant to be instructional or to be used as a guide. Anyone attempting any of these routes ought to have extensive experience in the backcountry and be able to evaluate changing conditions, difficulties, and all risks inherent to the sport. Furthermore, they should conduct thorough research and preparation before setting out.

Vitamin World assumes no responsibility or liability for any actions taken as a result of this post. Those climbing these mountains do so at their own risk. Climbers have died on each of the peaks and routes. Remember that visiting the backcountry and climbing summits is very different from casual day hiking and carries with it all the risks theirin.

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