Classification System
I like to highlight and markup some of my pictures for route clarification. Black lines= general directions, landmarks and/or Class 1 sections. Blue Lines=Class 2 sections. Red= Class 3 sections. Purple = Class 4 sections. Orange = Class 5. The class system is based on the YDS rating scale.
Approach
No matter how you slice it, approaching these peaks is a long affair. Cooper and Marten are located in the IPW, west of the continental divide and therefore don’t allow for easy access from the 4th of July or Brainard areas to the East. Can you backpack in from the East? Sure, but it’s a long trip up over Buchanan pass. The best approaches (still quite long) are from the West. I ended up making these summits part of a multi-day backpacking trip which allowed me plenty of time to explore around. Unfortunately, for a lot of people, backpacking isn’t always an option, so for those weekend warriors out there, the best and most direct approach would be from Monarch Lake or Roaring Fork Trailhead.
From Monarch lake go west on the Cascade Creek Trail, take a left on the Buchanan Pass Trail and another left up the Gourd Lake Trail. At Gourd lake head North above tree-line (passing Island lake en route) until you reach the saddle between Cooper Peak and the Continental divide. At the saddle, turn South and scramble the crest up Cooper, and then continue on to Marten. From Marten, find a line to descend East, crossing a basin with a few unnamed lakes before descending down to Gourd Lake. Then, hike the 8.6 miles back to Monarch Lake. Alternatively, you can climb to the saddle between Marten and Cooper from Gourd Lake (again crossing the unnamed lakes basin) and go one way to touch one and the other way to touch the other, but this route avoids all the fun scrambling on Cooper and doesn’t provide an easier ascent of Marten, which is Class 3 no matter what way you do it.
Another approach would be from the Roaring Fork Trailhead which saves distance but also involves an arduous ascent up to a saddle north of Irving Hale, before descending down to Stone Lake, and then re-ascending to the saddle between Cooper and the Continental Divide. Either way, its a 15-20 mile day if you want to hit both. Consider also, if you are from the Front Range, the 2-3 hour drive back via either Berthoud Pass or Trail Ridge. Approach how you will, I’ll start the route description from the saddle between Cooper and the Continental Divide, though there are numerous ways to ascend these peaks.
A NOTE ON CAMPING IN THE IPW: If you camp at Gourd Lake or Stone Lake YOU MUST obtain a backcountry permit for the wilderness, information is linked here. There is no free camping in the IPW unfortunately, and very limited places left where you can still have a campfire, PLEASE respect the rules. Both places are rugged and beautiful, pack out everything you bring in.
Secluded 12ers
Gerry Roach, author of “Colorado’s Indian Peaks: Classic Hikes and Climbs” has written about a few routes up these secluded summits. The easiest version is a 2+ climb of Cooper (ascending north from the saddle between Cooper and Marten) and a mid Class 3 ascent of Marten with exposure. These are NOT the only ways to climb them. Roach also wrote of a beautiful Class 4 South buttress as well as a Class 3 snow couloir climb up Cooper Peak, along with the route I chose, which he lists as Class 3 and calls the North Ridge route.
Marten Peak’s stately summit block has a number of routes that go from Class 3 to mid Class 5 on the N. S. and E. side, the West side looks super gnarly and probably has a few Class 5+ lines that I did not scout. For being such small mountains (by Colorado standards) the options are surprisingly plentiful on both peaks.
Since I was camping at Stone Lake, the easiest way to grab both was a loop, where I ascended up the saddle between Cooper and the Continental Divide, scrambled South to Cooper, continued South to Marten, backtracked to the Cooper/Marten saddle and descended North back to camp.

Approach stats (pulled from Gerry Roach’s book and AllTrails, use whatever source seems most accurate to you).
- Roaring Fork TH to Cooper: ~8 miles + 5300 ft.
- Monarch Lake TH to Cooper:
- via saddle “1”: 9.7 miles +3960 ft
- via saddle “2”: 10.2 miles +3960 ft.
- Cooper to Marten: .7 miles (-700ish ft to saddle, +400ish ft to Marten)
- Marten back to Roaring Fork Trailhead: ~7.2 miles (via saddle “1”)
- Marten back to Monarch Lake Trailhead: ~9.7 miles
Cooper (North Ridge Scramble) +variations YDS 3
Below is a photo of the saddle between Cooper and the Continental Divide and my initial ascent up to it, taken from Stone Lake. Part of Cooper’s charm is that it doesn’t look like much from, well, most angles. The peak is dwarfed by the massive hulk of the Continental Divide as it makes its way up to “Ooh La La” and Ogallala Peaks. It’s only when you get up to the top of the saddle that you see a more distinct profile.


Much better looking! The ascent route I took follows the blue arrows to harder terrain, hops around the top of the deeply inset couloir and up to the peak. I climbed it in early September and there was still a chunk of snow in there so June/July that Couloir would make a beauty of a snow climb. As if there weren’t enough ways to climb Cooper, you can also take the ridge-line up from Island Lake for another Class 3 variation if you come in from Gourd Lake area.
My route followed the initially simple ridge as it gained elevation over broken rocks and grassy patches. Nothing really exceeded Class 2 until I came up to what’s depicted in the picture below.

Since I was fresh and ready to scramble I wanted to see if I could stay on the ridge-line directly. The option to skirt is available and may be desirable if you’re trying to slam Cooper in a day. You do have to pick between the two options because to the left, the slope become almost immediately technical as the rock cascades down to the couloir. Below is a reference photo of where you are in the climb.

Choosing the ridge-crest took me on a surprising, exposed Class 3 jaunt that I really enjoyed. If you like to flirt with difficulties and can handle a bit of exposure this is a fun section of scrambling. It is NOT a hike, you’ll be using all fours.
The scramble can be broken down into 4/5 shorter pieces. Piece one is shown below and is simply attaining the ridge-crest via a series of low-to-mid Class 3 moves.

Once you get on top, you are greeted with a view of the impressive Cooper summit block and can enjoy a minute or two of Class 2+/ easy Class 3 ridge scrambling. The next piece is the most exposed and involves negotiating what I’ve called the 3 Guardians.

The Guardians are arranged like a right triangle and I’ll number them based off of which one you encounter first. The path of least resistance has you veer right around the first Guardian, hug an exposed set of rocks to the left side of Guardian 2 (the most exposed moves on this route are here) and then, hug another exposed set of rocks to the right side of Guardian 3. The pictures below help illustrate the moves.





Safely passed the Guardians, you’re treated to the view below.

Ascend the haystack rocks as shown in red and enjoy scampering across the ridge-line until you meet the head of the couloir and the base of the summit block. Once you pass the Guardians, there is another opportunity to bail to your right if you choose. I went straight up the ridge-line.


Below is a photo taken looking back to the Guardians as you circle the head of the Couloir.

From the head of the couloir, I took the first acceptable looking gully, we’ll call it Skyline Gully, just to the right of the edge of the ridge. The easiest alternative would be to traverse hard right around the steeper summit block until you find a lower Class 3 weakness and head up. The Skyline Gully runs mid 3 with maybe a 3+ move here and there.


At the end of the Skyline Gully is a brief break before a final 10 foot push up a set of slanted dark rocks. Before ascending to the final summit rock, I turned back to grab the below shot of what I’d done since the Guardians.



Thoughts: If the Guardians seem like a hassle, you can skirt around them, but you will still be required to perform an occasional Class 3 move to get up the summit, unless you circumvent around it entirely. If you’re up for it, give it a shot, the ridge line direct approach is exciting and will go if you take the time to find the path of least resistance.
Ridge to Marten
From Cooper, if you look south it’s hard to miss the distinctive profile of Marten Peak. Although roughly 300 feet lower than Cooper, I’d call it’s summit block even more exciting than Coopers. These are really fun mountains y’all.

From the summit of Cooper, make your way off the highest talus area. Careful route finding keeps the going at Class 2+ but making a couple Class 3 moves hustles the process along. Once on the broad grassy shoulder of Cooper, scoot down the ridge to the Cooper/Marten low point. Again, I tried to maintain a ridge-crest line and had a lot of fun doing so. Bailout options to the East (left) keep it at a 2+, while the ridge direct option sports solid Class 3 scrambling (with occasional loose rock) and a few Class 4 sections for the willing.

Sticking to the ridge was the most enjoyable choice as it avoided side-hilling and loose scree which, in my opinion, is worse than solid rock scrambling.
As you proceed towards the saddle, the scrambling on the ridge steadily increases, until you get to the Class 4 down-climb on the backside of the rock circled in purple below.




Just like that, you are at the saddle between Cooper and Marten. Pass to the left of the krummholz and begin climbing up the easy grass and talus slopes of Marten. There are a number of small towers along the way, the first big one is easily attained with minimal effort if you come in from the left hand side. Once you get in towards the summit block, Marten begins showing off it’s true character. It was a lot of fun messing around on the summit block.
Marten Peak: Summit Challenges
The going is fairly simple, and you pass a few knobs and small towers initially. Start paying attention when you get to the block depicted in the photo below. With time on my side I scouted three separate routes up the peak. I’ll start with the standard Class 3 (easiest) route, add a Class 4 variation and then include a third Class 4 route.

THE STANDARD ROUTE (YDS 3): As shown in the picture above and corroborated by Roach’s description, the standard route attains a wide ledge on the East side of the summit rocks, completely bypasses the true summit before pulling a 180 and looping back up the block from the South. The North-Direct scramble (Class 4) is an exciting alternative that starts from the 1st Notch. I’ll tackle that route a little later.

Once you pass the 1st Notch, the ledge continues along the side of the summit rocks, keep going. You don’t want to try and veer higher until you see “The Obelisk” depicted in the picture below. Any earlier attempt up will ultimately land you in Class 4/Class 5 territory.

In order to complete your 180 about-face, you have to hop up above a line of rocks. This can be accomplished with a few Class 3 moves and is illustrated below.



With the summit block now on your left, continue up the new ledge until arriving at a sandy chute that marks the easiest area to scramble left to the top.


F&T ROUTE (FINGERS AND TOES) Solid CLASS 4: Ok, so let’s say you wanted more spice on your ascent of Marten, fear not! I have options. Let’s backtrack to the area around the Obelisk, when you make that 180 degree turn on the standard. Per Gerry Roach’s description of the standard route: “Avoid the next 30 steep feet by performing an exposed Class 3 traverse around a corner to the east…” The F&T route is the 30 steep feet that the standard route avoids.



The two following pictures offer an un-labelled look from the bottom-up and then from the top-down.


Again, the route is not particularly long, but it is committing. I dropped my pack to ascend it, and felt fairly exposed until the last few feet. Exhilarating! Touch the top and descend via the Standard route.
NORTH RIDGE DIRECT (YDS 4): This route I’ve seen logged on a few trip reports in the past and it offers a great variety of moves. It is NOT the standard route which requires you to go all the way around to keep it at Class 3. The description for this route begins at the 1st Notch, as you approach from the North.



Once in the notch, veer left and begin climbing.



Once you pass above a small rib of rock after the brief Class 4 section, you arrive on the summit plateau and are treated to wonderful 360 degree views. Marten is a super cool little peak. Don’t forget to sign the summit register! The easiest descent is taking the standard down.

Below are two photos taken with my stronger camera from the summit of Cooper. They show the difficulties on Marten with the exception of the F&T route which is behind the summit rocks shown. Hopefully, this clarifies some lingering questions about the surprisingly complicated upper difficulties of the peak.


The summit block of Marten has a few loose rocks, so check your holds, but the F&T and the upper sections of the North Ridge Direct route are on solid slabs of rock which makes them really fun.
After hoofing it back to camp I was given the following look back to Marten from the shores of Stone Lake.

Like I said, just a cool set of secluded peaks. Next year I’ll attack Cooper from Gourd lake and hopefully have good conditions for an ascent of the South Buttress and/or the Snow Couloir. It would take very little convincing for me to then hop the 0.7 over to Marten as well.
Thanks for reading!