Researched route, Banff
Highway 93 South, Banff
A forest trail near Vermilion Pass to Boom Lake, and the way in to Mount Bell's slide paths and Boom Mountain's couloirs.
Boom Lake sits under the cliffs of Mount Bell and Boom Mountain in Banff National Park, a few kilometres east of Vermilion Pass on Highway 93 South, near Lake Louise. You follow the summer hiking trail 5.2 km from the Boom Lake day-use lot to the north shore near the lake's east end, and come back the same way, with about 245 m of climbing counting the many short rises. It's forest nearly all the way, and the last stretch runs under avalanche paths. The trail is the common way in to the skiing around the lake: the south-facing slide paths and treed chutes on Mount Bell's side, right above the trail's end, and Boom Mountain's steep north-facing couloirs and fans across the valley, with Kindergarten Couloir the best known of them. The trail gets you to the lake. Where you go from there and what you ski is your call. We built this route from research and haven't skied it ourselves.
We built this route from our own extensive research. All resources are cited on the dashboard. We haven't skied it ourselves, the routes illustrated may not be the best line choice, use your own judgement when planning. Remember you are still responsible for your own tour.
Last checked October 20, 2026.
| Distance | about 10.3 km round trip, 5.2 km to the lake |
| Elevation gain | about 245 m on the way in, counting the short rises (the rise from the car to the trail's high point is about 195 m), plus about 80 m of rises on the way out, most of it the climb back up from the shore |
| Slope angles | the ground under the trail is mostly under 20 degrees; above its last 2 km, slopes of 30 to 37 degrees on Mount Bell's side, and 40 degrees and more in Boom Mountain's couloirs; terrain data reads low |
| Trailhead | 1,727 m on terrain data |
| The lake | 1,890 m at the shore where the trail ends, on terrain data; the trail's high point is about 1,920 m, 4.3 km in |
| Nearest town | Lake Louise |
| Pass required | Parks Canada |
| Skied by us | Not yet |
Take the Trans-Canada west from Banff to Castle Junction and turn south onto Highway 93 South, toward Radium. The Boom Lake day-use lot is about 7 km along, on the right, north of the road. It's a big signed lot with washrooms, and trip reports find it busy in winter, with snowshoers as well as skiers. OpenStreetMap marks it as having no cell reception, so leave your plan with someone who isn't coming.
You need a Parks Canada pass to stop anywhere in Banff National Park, this lot included. When we checked Parks Canada's Banff bulletins in October 2026, there was no closure on the trail or at the lake. Parks Canada's intermittent avalanche closure zones on Highway 93 South are all on the Kootenay side of Vermilion Pass, west of this lot. When the headline of the regional avalanche forecast announces control work, those zones are legally closed, and Parks Canada can also close the highway itself for avalanche control. Check 511 Alberta and the Banff, Yoho and Kootenay forecast before you go.
The trail leaves from the back of the lot, crosses Boom Creek on a bridge, and climbs into the forest. The first 1.5 km is the steepest part, about 85 m up, with switchbacks and tight hairpins that trip reports single out on the way down. After that it climbs gently and steadily through big spruce and fir, with small rises and dips. Partway along, a signed junction points to Taylor and O'Brien lakes. Stay on the Boom Lake trail.
From about 3 km, steep south-facing slopes on Mount Bell's east ridge start to rise above the trail on your right. The trail tops out at about 1,920 m, about 4.3 km from the car. Then it runs west for about 800 m, some 150 to 200 m back from the north shore, under the slide paths coming down Mount Bell's side. Our runout model stops just short of the trail there, and real slides can run farther. A trip report describes skiing through one big slide path near the lake. The last 200 m drops to the shore, and the trail ends at the foot of a slide path, beside a field of big boulders, at 5.2 km.
The trail is the way in, and the skiing is yours to choose. Reports to Avalanche Canada's Mountain Information Network and a mountain guide's conditions report describe two kinds of skiing from here.
On Mount Bell's side, south-facing slide paths and treed chutes climb straight up from the trail's end and the shore toward the crest. Reports describe laps on them, from the first treed chutes near the lake up to the top few hundred metres of the big paths.
Across the valley, Boom Mountain's north side has steep couloirs with fans spread out below. Kindergarten Couloir is the one most reports name. They boot up the fan and the couloir and ski back down. Reports also ski the fans themselves and the north face further east. One report describes quick travel along the valley floor and the creek bed to Boom Mountain's side. We found nothing on where parties leave the trail, so we haven't drawn it. Ski tourers have also come out this way at the end of a long traverse from Chickadee Valley over the glaciers where the valley begins, which is a different trip.
Where the sources are thin, here's our own read of the terrain data. Mount Bell's side above the trail's end faces south and reads 30 to 37 degrees from about 1,950 m up toward the crest, above 2,500 m. Boom Mountain's couloirs face north and northeast and read 40 degrees and more, steeper again in the narrows, with fans that run out to the creek and the lake. Terrain data reads low, so slopes are steeper than they appear.
From wherever your skiing ends, get back to the trail. From Mount Bell's side, ski down to the trail or to the shore below the slopes and pick up the trail there. From Boom Mountain's side, come down the fans to the valley floor and back across to the trail the way you came over. Then follow the trail out to the car. From the shore it climbs about 30 m back to its high point, runs gently downhill through the forest, and drops more steeply over the last 1.5 km to the lot, with tight corners and switchbacks.
The last stretch of the trail is under avalanche paths. For about the first 2 km our terrain data finds no slope of 30 degrees or more within a kilometre above the trail. Past that, slopes that steep come closer, and from about 3 km they rise 150 to 400 m above the trail. From about 4.3 km the trail runs below the slide paths of Mount Bell's side all the way to its end, at the foot of one. Paths from Boom Mountain on the far side reach the shore as well. Slopes here are steeper than they appear.
Mount Bell's side. This is the skiing closest to the trail, and it's avalanche terrain from the shore up. In December 2022 reports describe shooting cracks as soon as a party started up an old slide path. In March 2024 most of the west-facing chutes on this side had slid, and a whumpf shook the trees on a slope of only 20 to 25 degrees, over a thick crust with weak, sugary snow underneath. In February 2025 a wind crust near 2,550 m, sitting on a sun crust, was quick to react. A guide's report in February 2022 found the crest above these paths stripped by wind and their start zones cross-loaded. On sunny days reports describe loose snow running off the sunny faces.
Boom Mountain's couloirs. Steep, narrow and north facing, with cornices above and rock walls that shed loose snow into them. In November 2025 a size 2 slide from high above hit a party booting just inside Kindergarten Couloir and carried one person about 100 m. Nobody was hurt. In January 2024 a skier set off a slab on a side wall pocket of the same couloir and was carried a long way down. In February 2026 a falling cornice released a slide on Boom Mountain's north slopes, about size 2 by the reporter's estimate. After a spring storm in May 2024 the couloirs had shed their new snow into the fans. Reports often find the fans full of old debris.
What the avalanche reports show. Reports to Avalanche Canada put most of the slides on Boom Mountain's north-facing couloirs and fans across the valley, and also on the south and west-facing chutes of Mount Bell's side above the lake. They describe loose snow off the steep walls, slides set off by falling cornices, and wind slabs, with shooting cracks and whumpfs on Mount Bell's side over weak snow lower in the pack. Most were natural. Reports follow where people go, and many people go to Kindergarten Couloir, so the record shows where people have been, not which side is more dangerous.
The lake. It may not be frozen early in the winter. A report in early November 2022 found it wide open, and another a month later still found slush in spots. A trip report describes slush and water on the ice out in the middle, and another source warns the ice is thinner toward the outflow at the east end. A report on the way to the fans found open water in places near the lake.
The trail. It's a hiking trail, not a groomed ski trail, and it's busy, with snowshoers and walkers on it too. The hairpins near the car come up fast on the way down. After windstorms, reports describe trees down across it: every 100 m or so past the Taylor and O'Brien lakes junction in January 2026. A trip report says the valley gets a lot of snow, so the first party out may be breaking trail.
On the trail it's mostly about getting through. Deadfall you can't get past, or fresh snow deep enough that breaking trail takes more than you've got.
Under the paths at the lake and on the slopes, look up. Fresh debris, whumpfs or cracking, heavy new snow, wind loading the start zones, a quick warm-up or strong sun on Mount Bell's south faces, or cornices hanging over the couloir you meant to climb. On the lake, slush, water or open leads.
Nothing on the trail commits you, so turning around anywhere on it only costs you the rest of the trail. Whether to go is your call on the day. Read the forecast and decide from what you find.
A gentle trail, and avalanche skills for everything past it. About 10 km and 245 m of climbing on the trail, plus whatever skiing you choose. The trail asks for control on a narrow, busy track with tight corners. Its last stretch runs under avalanche paths, and the skiing on both sides of the lake is avalanche terrain with a record of slides. We'd carry a transceiver, probe and shovel, know how to use them, and go with partners who do too. Boom Mountain's couloirs add steep booting and cornices overhead.
What we can't tell you yet. How the trail skis on the day, how busy it is, and how long it takes you. A trip report took about four hours in and out, with lunch and some time on the lake. The dashboard's estimate uses your own pace.