Rainbow Mountain
November 8-9, 2015
2314m
Whistler, BC
Rainbow Mountain is a rather isolated and prominent summit dominating the NW side of the village of Whistler, visible from almost every good vantage point nearby. In fact, over the past few trips I had my eyes constantly on this objective and some brief research led me to the conclusion that its standard route via Rainbow Lake can be served as a snowshoe trip once there’s enough snow to cover the boulder fields. A nearby summit unofficially known as “Gin Peak” can be used as either a “Plan B” or bonus objective. With this past Monday shaping up to be the only bluebird day in this week my decision was fairly easily made. The downside was obviously the arduous trail-breaking combining with the shortened daylight time and my solution was to knock off the approach on Sunday afternoon.

Rainbow Mountain and Gin Peak via Rainbow Lake. GPX DL
There’re two ways to approach this mountain – the traditional option from Alta Lake Road along 21 Mile Creek and the shorter route via Hanging Lake starting from near Whistler Olympic Park. I opted for the traditional route since it’s a bit more well-known hence I’d have less homework to do… I correctly located the trail-head after driving up the winding, but well-signed Alta Lake Road and started the approach at noon. There were a few branches on the lower portion of this trail and the general direction was to follow the most obvious one. After a while this trail ended and merged to a deactivated logging road and the original Rainbow Lake trail started from the end of this road. This trail was very well maintained except for the second critical bridge being removed… That creek was raging pretty high and I ended up wondering around for quite a while to find a reasonable place to boulder-hop across. After that bit of excitement I started to encounter continuous snow but thank to the work from previous parties the track was very packed down.
The lake was not frozen yet which was a bonus (more dramatic views) but the surrounding was already a world of white. Judging by the tracks I could see that most hikers stopped here but there were a few who pushed a bit further. I kept following the tracks contouring the lakeshore and after about halfway around I got tired of the post-holing and strapped the snowshoes on. Meanwhile the flurries had finally stopped and then I could see the weather starting to improve. But unfortunately for me the signs were all over the place saying it’s not allowed to camp by Rainbow Lake. The closest legal camping spot was directly ahead of me on the divide north of Gin Peak en route to Hanging Lake. The boot tracks stopped soon (too much post-holing for them) and I continued up to the ridge crest where I found a nice spot to camp on the opposite side of this divide. The post-holing was terrible even on snowshoes thank to the thin and rain-saturated snowpack combining with warm temperature.
The night was peaceful (windless and not too cold), but it’s such a long night to spend at this time of a year… Thankfully I had my iPod handy to kill time before eventually falling asleep by about 10 pm. The following morning I woke up just after it’s getting bright enough and started just before 7 am. I was pleased to see the dramatic improvement on the travelling condition after a deep overnight freeze. From camp I initially went up along the ridge crest but soon started side-hill contouring with slight down-hill travel back into the bowl above and north of Rainbow Lake. The main creek was still flowing so I grabbed my water there. Once across the creek I more-or-less maintained the general direction towards the broad pass ahead but went a bit higher on climber’s right. There were young trees and boulder fields creating lots of weak spots. I eventually got tired of this side-hill travel (more prone to sudden post-holing in those weak spots) and made a sharp turn to the right aiming straight up the slope. From here I basically followed the scramble route (as per Matt Gunn’s book) but the micro terrain was fairly confusing especially in the winter setting.
After negotiating a few more partially covered boulder fields the slope eventually narrowed down into a confined bowl where the wind started to slowly pick up… Good thing I forgot my balaclava at home and I had to constantly cover my face using my gloves… Brutal exercise but although the wind didn’t seem to die down it wasn’t getting any worse… From this bowl I veered climber’s left post-holing up a steep and foreshortened gully into the upper draw. There’s more micro terrain in this upper draw but at least now I had the view in sight of where I eventually gonna step onto the South Glacier. Some steep and careful traverses later I made to that point and got my first sunshine of the day. The wind finally died down too but the glacier was much bigger than I imagined with a few sizable crevasses visible.
I picked a contouring line avoiding that questionable area and made to a big wind scoop. Around the scoop I got to ascend the gentle slope straight up, exiting the glacier and onto the long undulating SW Ridge. The scramble route goes up the SW Ridge from here on while the ski route drops down the opposite side and ascends the NE Glacier. The ridge option appeared very steep while the NE Glacier appeared to have at least one major crevasse plus what seemed like a poorly bridged bergschrund. I opted for the ridge route. It’s indeed very steep but at least my Lightning Ascents were gripping pretty good on this type of terrain. In short time I arrived at the first highpoint.
There were more rime covered boulders on the ridge traverse making some careful foot placements (not wanting to break a snowshoe). Descending the other side of this first highpoint I arrived at a “small basin” where a few highpoints were visible ahead of me. I used my GPS to locate the true summit. I made my way trending to the right and then back left. I then checked off the other highpoints on this summit plateau just to be sure. The views were excellent but I couldn’t linger too long thank to the wind…
On the way down I simply retraced my tracks. Descending that steep section from the false summit to the col on the low point of SW Ridge was easier than I thought. After that it’s the fast plunge down the South Glacier. I took a long break on that wind scoop (sunny and windless) before resuming the descent. And as usual for snowshoeing trip I’d simply follow my tracks (or directly beside the tracks if it’s soft powder) hence the rest of the descent was fairly uneventful.
Back to camp it’s about 1 pm. It’s very temping to take a nap in the afternoon sun but given the good weather there’s no way to leave Gin Peak behind. It appeared like a quick 2-3 hours detour (but could have fair amount of post-holing) so after another long break I was off for the second objective of this trip.