Peter Rowat and company made the first one day ascent of Mount Slesse's Northeast Buttress, 5th overall, during the early seventies. What follows is Peter Rowat's route description from the Kootney Karabiner, Volume 16, 1973:
"...The climb takes the crest of the ridge all the way. 1 The most southerly point of Gimli, the start of the ridge and hardest pitch of the climb, consists of a curvaceous jam crack at the back of a 120 ft high steep wide chimney capped by an overhang. Can be well protected with nuts and exits right at the top to a stance beside the overhang. 2 Go straight up 6 feet then back left onto the ridge crest and climb easier ground to the first notch. 3 Go up to obvious flake, aim for the obvious crack but traverse round corner to right. 4 Continue to big flat step. 5 Continuous 5.6 for 200 ft going right occasionally, to stance. 6 Continue up circumventing overhang on left. 7-10 Ridge rounds off gradually, scramble to top. Rating: 5.7. Gear: 6 pins from small horizontal to 1 1/2", 12 nuts."
ADDITIONAL ROUTE DESCRIPTION
High quality gneiss is climbed directly up the fin shaped southeast ridge of Mount Gimli. Since we use the Yosemite Decimal System, I like to use Valley routes for comparison. My crack-hating wife thought the crux first pitch to be much harder than Bishop's Jamcrack (5.8) and much easier than pitch two of the Central Pillar of Frenzy (5.9).
Start climbing left of the pack-stash ledge, up delicate but easy slabs, 20 feet left of the main crack system. Climb the excellent white corner passing a roof with good holds and strenuous pulls out right. 35 meters up, there are about ten slings, with rings, around a flake for a rappel anchor. Better to belay on the ledge a few feet above the slings. Anchor in the main crack on the left. Beware of the hollow horizontal crack that appears to anchor the better part of the ledge.
The second pitch climbs up to the ridge using thin cracks and dark gneiss band holds. About 5.7 to start, then easing up to a notch/Gendarme belay with a slung chockstone.
Pitch three climbs more gorgeous, steep, and tricky banded gneiss. End at a tree and nice ledge on the ridge (5.7, see photo).
Pitch four is again steep and beautiful, with a hard lieback move. End atop the grassy and comfortable "Lunch Ledge" (5.6+, 60 meters).
Pitch five is again fun and exposed for 60 meters to the base of the notorious roof pitch (5.8).
Pitch six starts with a short corner up the the roof move. Left around the roof up to a small ledge (5.10a move).
Pitch seven is the last of the fifth class climbing. Two hundred feet, with more nicely sculpted rock, up to a belay below the "diving board" (5.7).
A long stretch of class III ridge leads to Mount Gimli's sub-summit, then a notch, and finally a class II scramble to the true summit. Go to the Mount Gimli page for descent beta.
OTHER WEB BETA
More good beta for the Valhallas can be found on
sTePh aBeG's site.
Good pictures in this 2005 Valhalla trip report from Idaho.
Pellucid Wombat posted a trip report for Gimli on Supertopo