The Whitehorn Back Bowls are the once glaciated and wind-sculpted terrain on the backside of Whitehorn Mountain; the technical benchmark for Lake Louise Ski Resort’s advanced and expert offerings. Access is via the Summit Chair, which provides lift access to high-alpine ridges; the transition from groomed Front Side slopes to the Back Bowls crosses Windy Gap; a narrow col notorious for wind-scouring.

Orographic influence and snowpack. Prevailing westerlies lift moisture across the Continental Divide and deposit dry powder into lee-side basins; Boomerang and Upper Boomerang (formerly Hikers Paradise). This wind-loading is not merely desirable for powder skiing but a functional requirement; continental snowpack (mean winter temps −15°C to −25°C) promotes depth hoar near the ground; wind-deposited slabs “cap” weaker layers and stabilise the base. Annual snowfall ~430 cm (171 in); wind-loading and snow farming compensate for relatively shallow totals.

Boomerang corridor. Boomerang (Run #133) is the primary egress from the Summit area to the Paradise Chair and Ptarmigan Chair. The Leg Burner patrol race; a word-of-mouth endurance tradition; runs from Shoulder Roll through Boomerang to the Ski Out and base-lodge stairs. Designated intermediate (Blue); average pitch ~24°; vertical drop 1,188 ft; length ~1.5 miles. Wind-loading often produces “creamy” packed powder. Upper Boomerang (Run #135) is the advanced extension; single black diamond; pitch to 29°; vertical 180 ft; staging for Brown Cow (formerly Brown Shirt) and Boundary Bowl; Upper Boomerang also includes the former Hikers Paradise hike-to apex.

Windy Gap bottleneck. Skiers exiting the Summit Chair must traverse Windy Gap; a narrow col funneling wind and often scoured to bedrock even in mid-winter. Early season: resort may require skiers to remove skis and walk across rock. Snow farming (wooden and plastic fences, trail-crew snow placement) combats scouring; the traverse and egress paths are groomed even when the bowls remain ungroomed.

Upper Boomerang (formerly Hikers Paradise). Upper Boomerang (Run #135) includes a hike-to apex; 15-minute boot pack from the Boomerang traverse; no lift reaches the top. Technical lines include Wild Gully and Ghostly Gully (narrow chutes; sensitive to snow depth); North Cornice (lee-side cornice used for airs); upper Boomerang Bowl (open powder). Avy control focuses on cornice management. Distinguish from summer Hikers Paradise hiking trails; different area; subject to wildlife closures.

Summit Platter to Chair transition. The Summit Platter (T-bar, 1975–2020) required balance and strength; a natural filter. The Summit Chair (2020, Doppelmayr quad) democratised access; higher traffic on Boomerang but Upper Boomerang’s hike-to apex remains protected by the boot pack. West Bowl and Richardson’s Ridge expansions disperse skier volume.

Avalanche governance. Control at Lake Louise reflects a broader shift in Canadian mountain governance. From the 1950s through the late 1970s, Park Wardens; bolstered by Swiss guides like Walter Perren; performed all forecasting, blasting, and patrolling for the resort. The founding of the Canadian Avalanche Association (1981) enabled certification of private-sector professionals; by the late 1980s, operational control (day-to-day blasting and run-opening decisions) had passed to resort Snow Safety teams. Check resort website for real-time status.