Climbed by: me, Kevin.
Park in the Highwood Meadows parking lot (there are washrooms here). The Ptarmigan Cirque Trail starts at the north end of the parking lot. Turn right at the intersection, and (carefully) cross the highway. On the other side, the trail goes up for a bit, and emerges in a beautiful valley.
We saw at least 50 sheep today, some along-side the highway, but most of them in this meadow. We also saw a pair of grizzlies a few kilometers north of the parking lot beside the highway. I made sure my bear banger was locked and loaded, and my bear-spray was handy!
Follow the trail to the back of the cirque, and the end of the trail (which is marked with a super-obvious sign). All of the descriptions I read about the Mt. Rae ascent trail indicated that it was faint. Those route descriptions must be old because the 'scramblers' trail is now as obvious as the main circle trail, at least at the beginning. Turn left onto the scramblers trail, and go up the hill, and around the ridge toward the left. The tail leads steadily, but not steeply, upward for probably a kilometer, and then starts to get steep, and the scree gets smaller and more annoying the higher you get.
By the time you get to the end of the valley, it becomes pretty obvious that you need to gain the ridge by either scrambling up some steep scree, or climbing one of the rock bands near the top. I started to work my way over toward the small shelf on the extreme climber's left of the col, while Kevin worked his way toward the first (largest) spine of rock on the right. After getting closer to the shelf, I decided Kevin's way looked far better than mine, and scrambled/slid over to join him. This turned out to be an excellent ascent route to the top of the col, though there was a small amount of loose rock present, so I'd have to recommend a rock helmet, even if there's no one ahead of you, just in case.
We gained the ridge in no time, and stopped for a food and water break (and a couple of photos). The ridge from here looked fairly interesting, but there was an obvious trail leading across the scree below (climber's left) the imposing gendarme blocking the ridge. The route descriptions indicated that you would 'scramble' underneath the gendarme, but the trail is well trampled and cannot be missed unless maybe there's snow on the ground, or really dense fog. At this point we noticed that there was quite a bit of smoke in the air, and that you couldn't see diddly -- everything more than about a kilometer was a ghostly spectre, barely visible, and of anything beyond that there was absolutely no sign. We were somewhat hopeful that we'd climb above the layer of smoke (you could see it ceiling out about 1000 feet above the nearby summits).
We walked along the trail, and ended up taking the lowest route. Anyone reading this would be wise to go UP at the first rock rib intersecting a trail over the rock, then follow the diagonal trail leading upward to the next (larger) rock rib, crossing that one quite a ways above the lower trail. We ended up scrambling up some loose crap rock/shale below a butress on the ridge, and while it worked out okay, I think we'd have been better off heading up diagonally rather than straight up at the end.
Once we got up to the rock butress, we skirted around the right-hand side of it, and scrambled up onto the ridge again. I'm glad it wasn't a windy day, as there was some interesting exposure to deal with, and the wind would have complicated things a bit. It did look like there were ways around (under on the climber's left) most of the fun parts, but we didn't try any of those, so can't say if they're good or not.
At this point we were maybe 50-75 meters vertical from the summit. We walked up the ridge, and before we knew it, we were at the top. Near the summit, Dave caught up to us and passed us, so we weren't the first ones on the summit that day, but we were close!