This route offers climbers the chance to make a grand tour of the mountain without retracing any steps (except for a few at the very beginning). About half of the route coincides with the northwest ridge route. This route is only a little bit longer than the northwest ridge out-and-back route and will probably be much more enjoyable to most climbers for its variety of terrain and scenery.
About 5 miles north of Choteau on U.S. 89, a paved road indicating skiing and fishing access heads left. Take it. About 17 miles later, take a left turn that shortly crosses the South Fork Teton River and becomes a gravel road. This is the South Fork Teton Road, and you follow it through increasingly pretty scenery for about ten miles to a parking area at its end. The parking area is about 1 mile past the turnoff for the Mill Falls campground and recreation area. Mill Falls takes only a few minutes to see and is pretty but not heart-stopping. On the right side of the road at the parking area, you will find the trailhead for Headquarters Creek Pass and Our Lake. These roads are passable for passenger cars.
This is a loop of about 9.5 miles, 6 of it on maintained trails. Elevation gain from trailhead to summit is about 3000', with very little elevation lost and having to be regained unless you climb the peak between Point 8987 and Headquarters Creek Pass.
The route works well in either direction, but I recommend going to Our Lake first. The lake is beautiful (and best for photography) early in the morning, which is when most day climbers will be there. Also, you will be going uphill on the better scrambling sections, which will be easier, safer, and more enjoyable.
From the parking lot, the trail climbs 3 miles and 1500' to Our Lake, offering some great views of Rocky Mountain and passing a lovely waterfall along the way (best in early summer, nearly dry by August in some years). Early on into the hike, you reach a junction; left goes to Headquarters Creek Pass and right goes to Our Lake.
Stay a little bit at the lake and admire the scenery. Enjoy it all the more since there are few lakes in the Rocky Mountain Front. Scan the slopes around you for mountain goats. Look to the west for the 7800' saddle you have to reach; it is about 500' higher than Our Lake and approximately a mile west of its outlet. When you are ready, travel around the north side of the lake and climb west on a grassy slope featuring a few stands of trees. There should be a use trail most of the way from here to the saddle, but if there isn't or you can't find it, just head west and try to minimize your impact on the meadows. The only way you could get lost would be if there were thick fog and you had absolutely no sense of direction. Take a rest, check out the views, and start planning your way up the northwest ridge. It is about one mile and 1000' of elevation gain to the summit.
From the saddle, look up and to your left and start going. There is no one right way up the ridge and to the summit, so choose what seems to you to be the path of least resistance while staying as directly on course as possible. In general, the closer you are to the crest of the ridge, the better the footing and the more solid the handholds when you need them. The majority of the route climbs talus slopes, but you sometimes encounter rock bands or outcrops that require some Class 3 scrambling that most people comfortable with climbing will find pretty easy. The way I went, I ran into only two spots that were slightly tricky, one of which involved a little downclimbing to easier terrain, and neither section offered deadly or even significant exposure. Yes, a fall would have hurt and maybe been worse if I'd landed just right, or wrong, really, but there were no precipices threatening little spills of hundreds or even dozens of feet. The biggest danger on this route, aside from exposure to lightning, is probably twisting your ankles or being hit by rocks dislodged by human or goat climbers above you.
More than once, you will think you are approaching the summit, and more than once you will be wrong. Eventually, though, my route (mostly on the west side of the ridge and on or just below its crest) took me out onto a wide-open talus slope that offered an easy ascent to the ridge's crest, and then it was a simple walk for just a few minutes more to the summit. A cairn at the summit will dispel any notions that nobody else has ever been where you are, but no matter-- few people do come here, and the sense of remoteness and the sweeping views you get make you feel as if you really have stumbled across some undiscovered country. On display are the two titans of the Sawtooth Range-- twin-summitted Old Baldy (north) and Rocky Mountain (south). Your jaw may drop as you level out and see these mountains in their full splendor.
From the summit, it is about a mile to 7743' Headquarters Creek Pass. Descend to a saddle between Point 8789 and an unmarked summit east-southeast of it, and then either bypass the summit (enjoy the talus sidehilling) or hike up that second summit to continue to the pass. Again, it is mostly Class 2 with some easy Class 3 sprinkled in, and there are no significant obstacles.
The trail from the pass winds for three miles first through a beautiful subalpine basin below Rocky Mountain and then through forest back to the trailhead. If the time, energy, and interest are there, though, consider first climbing Rocky Mountain while you are at the pass.
Good hiking boots, windbreaker and sunglasses, trekking poles (maybe-- I think they just get in the way as soon as things get tougher than Class 2).