Mt. Brennan The Not Exactly Straight Forward WayI say the not-exactly-straight-forward way, but let me be clear, the way to completely simplify your experience is to use a snowmobile. We are foreigners, and sadly, we don't have a snowmobile.
I'm from Oregon (another place one ought to have a snowmobile), and have spent a few weeks at a time in the Kootenays nearly every winter for the past four years. Brennan has been on the radar as a beautiful big objective and with the recent stability and clear weather, my partner and I decided it would be worth it to get up high and enjoy the crust. We spent a few hours route planning, cross referencing slope angle shading, topo maps, and google earth. Upon initial inspection the only questionable part of the up would be the first 500m or so. Having toured in the area a few times I knew we'd be starting from the highway, so I foolishly assumed a parking solution would be obvious upon arrival. Monday morning arrived and the alarm went off at 4:00am. We ended up parking an the Rossiter FSR junction, reasoning that the road to the TH would be faster travel than bushwacking and eliminate any creek crossings (truthfully this was my partners suggestion, and I secretly resent him for it - he didn't use the beta on this site). Skinning by 6:30, we immediately started going downhill. Since we'd assumed the FSR would steadily gain elevation, this was pretty frustrating, but not frustrating enough to make us charge up the roadcut... so we slogged on. The road began to climb after crossing Rossiter Creek.
(Sunrise and a bit of a cloudcap)
To our ever growing frustration we began going downhill again immediately after reaching the trailhead. At this point, the conversation of how pathetic we were and if we should bag it all together was had, given that we had been skinning for about two hours and only netted 500m of vert. Spirits lifted once we linked up with the route we should've taken on the other side (west side) of Lyle creek (snowmobile-able). The pace picked up once we hit the lower headwall before the lake.
(Lyle Lake sites in the basin above)
We hit the lake at 10:30 after four hours of skinning. The stretch from the TH to the lake had an established skin track and a fair amount of tracks, as well as a bomber sun crust and some impressive point releases from the rocks on east-facing wall of the bowl. From the lake there was an older skin track that had been covered by ~10cm of snow that followed the hiking trail up the first gully north of the lake. Once out of the gully we encountered an unexpected gift - POW! About 15-20cm of soft dry goodness cached on the east aspects between 2100m to 2400m. Per the forecast, we observed very little evidence of the PWL above the lake, but there was obvious windloading on the S-SE facing ribs where drifts had completely buried the previous track.
(The long-lost goodness)
The snow surface turned into sastrugi with some creamy bits and a sprinkle of rime once we climbed above the entrance to the south bowl. We hit the summit a little after 1:00PM in cool temps with a moderate northwest wind.
(The summit views were truly spectacular)
We had originally planned on taking a peek at the south bowl on our ski down and potentially skiing out that way, however, the cold dry snow we'd seen on the way up was too tempting. We figured the south bowl would be quite crusty and the lower ramp out even more heinous in comparison, so we opted for some of the deepest pow turns yet this winter (a sad reality). Back at the lake, the crust battle began.
After slash turning and a bit of prayer we arrived at the trailhead ACL's intact. Disgruntled that we now had to put our skins back on, the 5-6km road slog with more unnecessary climbing crushed our spirits even more. The plan was formulated to ski the clear cuts, jump on the road until it crossed Rossiter Creek and then dive off fall line toward the highway before the road went uphill. Needless to say, this was a bushy dripline skate and we paid for it by snapping the tail of a Fischer Hannibal on a wild backseat turn in between two cedars. Back at the car with three of four skis intact and thankfully four of four eyeballs, we wearily mused about our terrible route finding.
NOTE: Use the beta listed under the route section on this site - don't do what we did. If you do you can plan on a hair over 24km roundtrip and a 2300m day.