Big Choss – Alberta Bouldering: A Beginner’s Guide

Approximately 45 minutes west of Calgary and 20 minutes east of Canmore lies one of my favorite Alberta bouldering areas – Big Choss. A large limestone boulder field nestled at the base of Mt. Yamnuska, in the Bow Valley.

As you may guess from its name, Big Choss is known for its loose, rotten rock. But fear not! There is plenty of prime rock to sink your teeth (er, hands) into! There is some pretty polished rock in the more popular areas, and some highball lines may seem intimidating at first glance, but this is an excellent area to start honing your skills and building some super tough skin.

Expect to get your skin chewed a bit. After-all, what’s a day of climbing if you come home with all your skin anyways! The rock tends to be quite sharp and jagged in many areas – you may want to leave your fancy Lulu’s at home for this one.

Big Choss Approach

Big Choss Approach

Getting There

From Calgary – Take Highway 1 west, approx. 45 minutes to exit 114, AB-1X N. Go north to highway 1A, Bow Valley Trail. Turn right on 1A and The Yamnuska Parking lot will be on your left as you head north.

  • Alternatively, take Highway 1A from Calgary, approx. 45. The Yamnuska Parking lot will be on the right hand side.

From Canmore – Take Highway 1 east, approx. 25 minutes to exit 114, and continue north as per-From Calgary.

  • Alternatively, take highway 1A East, approx. 25 min and the Yamnuska parking lot will be on your left.

Approach the boulders via the gated mining road. Walk from the Yamnuska parking lot to the open quarry. As you round the west side of the quarry, cross the clearing, and a well-worn trail awaits as you enter the woods. Follow the trail for a short approach to Fairy Boulder, the first area in Big Choss.

When & Where to Climb

Big Choss is accessible year-round. A warm winter Chinook may allow for winter climbing when snow-fall has been low. You may want an early start in the summer, as the south-facing slope is well exposed to the sun, and can heat up quickly.

Bouldering In The Canadian Rockies has all the climbing info on this area, including tops and area maps. It is available around Alberta and online. Navigating the area can be a bit intimidating at first, and it isn’t hard to get turned around. So take your time, and check the maps often. It is an area that you can easily explore on your own, but having a partner who knows the area may open up secrets that the book won’t show.

This area is over-flowing with moderates. V0-V4, and up to V9’s for later projecting! Here are a couple – located throughout the south half of Big Choss – to get you started… (Based on Bouldering in The Canadian Rockies guide book info. Use it as a reference).

Fairy Boulder “#2”, V1 – Scared of slab? Here’s a great way to break that! This higher slab line follows a great crack straight up the side face of Fairy Boulder. Dig your toes in, get that butt in the air and lean in to it!

Emily Carpenter - Fairy Boulder V1

Fairy Boulder V1

“Warmup Boulder” – Lesser Slabside area, V0-V4 – A great place to shake off the jitters. Continue west past Fairy Boulder, cross the small, low-lying fence, and move into Lesser Slab Side. When you reach the main boulder – right on the trail – take the trail bend up the hill. The boulder can be a bit tricky to find at first – it is off to the right up the hill.

The east face boasts lots of options. Two arêtes, a great traverse line from the lower left and up to the right, and many options flat on the face. Choose your own adventure!

Emily Carpenter - Warmup Boulder Arete, V0

Warmup Boulder Arete, V0

Lower West-side Area: “Crack of Don”, V0 – The giant lightning bolt shaped, south facing crack is great fun. A sketchy-looking section on top is quite secure, and makes for some fun under-cling action as you top out.

Alexis Jones - Crack of Don, V0

Crack of Don, V0

Guano Area: “Waking Up to The Crack of Don” V0 – An epic highball slab, with another stunning lightning bolt crack up the middle. Good spotting and well placed pads on this one, and the landing is one of the less appealing in the area. This line is a great chance to practice your slab footwork, flagging and crack climbing skills.

**Note, this line is not currently found in the guide book. Find it hiding on a west-facing boulder on the far west side of the big clearing in Guano Area.

Kim Appleby - Waking up To The Crack of Don - V0

Waking up To The Crack of Don – V0

Culo Boulder “Culo Arete” – Sit start and move up and out the arête using some nice combinations of jugs, pinches and crimps. Great feet. A nice intro to a more over-hung climbing style.

Culo boulder is easily missed, but can be found directly east of Guano area and North of Lower Westside. A few nice, big trees tuck Culo into its own little world.

Alexis Jones - Culo Arete, V2

Culo Arete, V2

Big shout out to my beta testing crew (and models) on this – Kim Appleby, Alexis Jones and Emily Carpenter.

Kim Appleby - Waking up To The Crack of Don, V0

Waking up To The Crack of Don, V0