Twenty-five miles north of Cody, Wyoming, at the mouth of historic Clarks Fork Canyon, stand imposing 2,000’ slabs of pale blue Madison Limestone. Remnants of an ancient seabed that covered the Intermountain West, most of this rock is exposed through canyons and faulting in a cross-section of its layers. The slabs at the mouth of Clarks Fork, however, are actually tilted by the bulging of the Yellowstone Plateau. The rock is smooth and undulating like the sea floor it once was, and the quality is more akin to that of the Verdon Gorge than the broken crags of Rifle and Logan canyons.

My friends and I learned about Clarks Fork limestone some 30 years ago from Cody resident Bobby Model. Despite his claims about the high-quality rock, the notion that it was less than vertical kept our young, strong arms from turning the steering wheels in that direction. Bob tragically passed away after a car accident in South Africa in 2007, and despite the odd new route up obvious gullies and weaknesses (most with large runouts) at the mouth of Clarks Fork Canyon, there has been little real development.

Meanwhile, as the years and scar tissue accumulated during the last three decades, close friends Mike Lilygren, Shep Vail, and I have altered our primary focus in route development: Whereas once we wanted to create personal testpieces for our peers, we are now pursuing something a bit more egalitarian. The code has become: “The experience of the second ascent is more important than that of the first ascent.” That is, the climbing experience doesn’t have to be difficult, per se—it should be fun.

Our first route at Clarks Fork, in the fall of 2019, embodied this approach. It was a 12-pitch affair on a rib of extremely solid rock. For the most part, the rib had ledges every 25–35m, allowing for comfortable stances from which to belay and rappel. The odd crack or dihedral gave most pitches optional gear placements, and in a few places there were runnels that could be protected much like a crack. We bolted all the cruxes and then added additional bolts in several spots to make the climbing safer and more accessible at the grade (versus leaving long sections of unprotected moder- ate climbing). The crux of this route—which we named Colter’s Rib, after trapper John Colter, who passed under the wall in the winter of 1808—came in at 5.10c. Most pitches were in the 5.7 to 5.9 range.

From the top of that route, we walked through forest and scree to reach the north- east ridge of an obvious spire, which we called Colter’s Spire. The rock here was less solid, but some of the climbing was excellent, and the airy summit was worth a little choss. We topped out after four pitches, all roughly 30m, and none of them harder than 5.8. The route is mostly bolt-protected, but requires a light rack.

On our next trip, in the spring of 2020, we turned our focus to a much bigger spire to the north. Broken into four distinct bands of rock, each roughly 400’ in length, this route got harder as we went higher. To complete this project, we used hundreds of feet of fixed line and bivied in a cave about halfway up. The route topped out on a tower we dubbed Chief Joseph Spire, for the Nez Perce chief who led his people away from the U.S. Cavalry via Clarks Fork Canyon. We named the route Forever (21 pitches, 5.11d), based on one of the chief ’s speeches. The hardest pitch can be climbed by a 5.10
leader by hanging his/her way through the crux on bolts.

Our third line, opened in the fall of 2021, ascended Buffalo Horn Spire, named for a Bannock chief who fought and lost a nearby battle with the U.S. Army. (This spire was first climbed by Justin Willis, by a different line.) Our route, M11, is 22 pitches with a 5.11c crux that can be climbed at C0; there are some obligatory 5.10 sections. M11 is named after the aforementioned Bobby Model. As with all the routes we have established at the Mouth, a light rack is useful despite ample bolts.

Mike, Shep, and I have a very tight relationship, and it seems to get stronger with each new route we do together. We always agree on the line, and generally begin answering each other’s questions just before they get verbalized. It’s a really cool camaraderie that comes from thousands of hours of climbing together, and makes the sport that much more enjoyable. I’ve come to realize that while the competitive days of youth were fun, doing moderates with my closest friends is even better.

We established all of these routes in a hybrid style, with some pitches climbed bottom up, others cleaned and equipped from above. We climbed many pitches in a run-out style, then added bolts later to make for enjoyable future ascents. All bolts are stainless steel, and all rappel anchors are set up so that they do not require parties to add or replace webbing.

— Sam Lightner Jr.

Editor’s Note: Pitch-by-pitch descriptions of these routes and other useful information are posted at Mountain Project. Lightner, Lilygren, and Vail also established an 11-pitch 1,400’ 5.9 called Back Pain, but described it on Mountain Project as “a bad route that should not be attempted unless you like loose rock and fractured climbing. We note it because it has been climbed.”