Sentinel Pass is a high mountain saddle at 2,611 m (8,566 ft), the dramatic notch between the southwest face of Mount Temple (3,544 m), the highest peak in the Bow Range, and the jagged spires of Pinnacle Mountain (3,067 m). It links Larch Valley and Paradise Valley and offers some of the best larch viewing in Banff National Park.

Stats. Roughly 725 m elevation gain from the Moraine Lake shoreline. Distance: 5.8 km one way, 11.6 km round trip. Location: 51.3299° N, 116.2011° W. Samuel Allen first looked down into the Valley of the Ten Peaks from here in 1894 and named the peaks using Stoney Nakoda numerals.

Trail. The Sentinel Pass trail ascends through three phases. Phase I: roughly ten steady switchbacks through dense subalpine forest (Engelmann spruce, subalpine fir) on compacted dirt and roots. Phase II: the gradient levels in Larch Valley; a soft, loamy path through meadows past the Minnestimma Lakes, a pair of shallow tarns that reflect the surrounding peaks. Phase III: the final kilometre narrows and steepens into tight switchbacks cut into scree and talus; footing is shifting and technical. Trekking poles are recommended for the 200 m vertical push. The pass is the highest maintained trail point in the park.

The Sentinels and geology. The pass is named for towering rock pillars (pinnacles) that stand as remnants of erosion. The dominant rock is Gog Group quartzite and sandstone, roughly 500 million years old (Cambrian). The Grand Sentinel, a free-standing pillar visible looking down toward Paradise Valley, formed by differential erosion and frost wedging; water enters vertical joints, freezes, expands, and slowly pries blocks away. Softer surrounding rock fell away, leaving the Sentinels as isolated towers.

Ecology. Larch Valley is premier habitat for subalpine larch; needles turn gold in late September. The corridor is critical grizzly bear habitat (buffaloberries, glacier lily); Parks Canada often enforces a mandatory group-of-four restriction. In the talus, listen for American Pika and watch for Hoary Marmot sunning on boulders.

Views. South: the Valley of the Ten Peaks, Mount Fay, Mount Little, Mount Bowlen. North: a precipitous drop into Paradise Valley; the turquoise Minnestimma Lakes behind contrast with the shadowed depths. Look for Eiffel Peak to the southwest and the “black towers” on the lower slopes of Mount Temple.

Advanced routes. For experienced scramblers, a faint trail breaks east from the pass toward the southwest ridge of Mount Temple; a perilous Class 3 scramble with rockfall and exposure. Helmets mandatory. Advanced hikers may descend the north side into Paradise Valley instead of retracing; the route is steeper and less defined, eventually passing the Giant Steps (waterfall terraces) before exiting near the Fairview Mountain base. Avalanche risk can persist into summer on the north-facing slope; check conditions before hiking.

Safety. Weather can shift from clear to localized blizzard in under 20 minutes; carry a hardshell. The pass is highly exposed to lightning; descend immediately if cumulonimbus build or you feel static. No potable water above Minnestimma Lakes; filter any water from the tarns.

See Lake Louise and Moraine Lake Trail Systems for shuttle access and the full trail network.