In September, Alex Marine and I climbed a line up the pillar that forms the lower northeast ridge of the east subsummit of A Peak (8,634’) in the Cabinet Mountains Wilderness of northwest Montana. We’d been intrigued by the recent impressive ice and mixed ascents in the basin (see AAJ 2019), by our own summer reconnaissance years earlier, and by a relatively easy approach.

The eastern aspect of A Peak is a complicated collection of radiating ridges, gendarmes, pillars, and faces, with about 2,400’ of fifth-class rock leading to the main summit. The rock consists of bands of quartzite, argillite, and siltite, splotched with lichen in shades of white, pumpkin, and chartreuse. Dan Doody and William Echo were the first to climb a technical line to the main summit, in 1962, and we would be surprised if others haven’t traced rock routes up the mountain.

As Alex and I circled Granite Lake at first light, two beavers cannonballed into the lake from a small rock jetty. One of them sallied forth directly toward us and then swam alongside near shore as we gingerly straddled stands of devil’s club at the water’s edge. Perhaps the beaver was offering safe passage. Perhaps it was warning us about the midden of snafflehounds—bushy tailed woodrats—who would invade our bivouac ledge that night. 

Our route traced a line up the center of the obvious large pillar below the east subsummit. We followed lower-angle entry pitches for about 600’ (5.6–5.8), then a 300’ chimney-corner system on the left side of a red pillar (5.10+), including a neat keyhole slot that required the leader to take off both rack and pack to squeeze through. Another few pitches of fun corners and faces brought us to 300’ of tricky route-finding, with cruxes pulling through overhung arêtes (5.11) to avoid large roofs that capped each corner. Two more pitches of pleasant corners (5.9) penetrated the final roof system to the flat top of the pillar (7,740’). 

We named our route Castor Sally (1,900’ climbing distance, 13 pitches, 5.11). We chose not attempt the upper ridge to the main summit given a snowstorm forecast for the following day. A dozen different lines could converge at the top of this pillar, and the character of the climbing changes above here, with a series of gendarmes on the upper winding ridge that are not obvious from the ground. Adjacent ridges also showcased impressive turrets and cockscombs. 

What stands out about the mountain are dozens of dihedrals and open corners on the north and especially south aspects of the various ridges and pillars. These features would likely reward more exploration. Our rappel line down the pillar’s south side passed over largely clean rock, with good face holds adjacent to dihedral cracks for protection. That said, any long route is likely to encounter stretches of choss. Roofs are generally too loose to pull through directly, arêtes are often blank or unstable, and sheer faces are climbable but lack cracks even for knifeblades. Choose carefully.

Overall, one might say the quality of the climbing is marred by stretches of loose rock. One might as easily say the loose character is brightened by stretches of quality, compact stone.

Is the rock on A Peak “A-plus”? No. B-minus? Sure. Pass or fail? Yes. If A Peak were in parts of the Canadian Rockies, would it be a local semi-classic? Fair question.

– Spencer Gray