Arethusa Cirque Trail

Arethusa Cirque is an unofficial 2.45-mile loop from a gravel pullout on Highway 40 into a creek-cut alpine meadow, around the rocky basin and back through the trees. The climb is about 920 feet, and the high point is an open slope below the surrounding peaks, not a summit or built lookout. Allow two to three hours. The mileage is short, but this is a real mountain walk: the tracks are unsigned, several creek crossings mean rock-hopping, and one short slope is steep and loose. Published accounts range from about 2.5 to 3 miles as people follow different braids and loop choices; this length follows the shorter full cirque circuit and leaves out the separate Little Arethusa and Mount Arethusa scrambles.

The trail starts at the north end of a broad, unmarked gravel clearing on the east side of Highway 40, about 1.4 km south of the Ptarmigan Cirque parking area. A gentle path winds through forest for roughly 0.7 km. Roots and mud can make this lower stretch slick, and a small waterfall appears shortly before the trees open onto the meadow. The creek is the first big change: you leave the shade, reach the water above the falls, and get your first full view of the cirque.

At the creek, several faint tracks branch. A middle path is a shortcut; the outer circuit keeps going around the basin. Other tracks climb toward Little Arethusa or Mount Arethusa, which are separate, much more demanding scrambles. There are no signs to sort them out, and the tracks braid over open ground, so save an offline map and check it at each fork. The two directions have different tradeoffs: a short, steep dirt slope is awkward when wet, and hikers disagree about which way feels easier. If you would rather climb that slope than descend it, choose your direction accordingly.

The upper loop leaves the creekside meadow for loose rock and scree below Storm Mountain, then crosses more open, rocky ground. Watch where you step; the tread can fade among gravel and low shrubs. The descent drops back toward forest and the creek, where a final crossing brings you to the approach trail. The circuit is not a technical summit route, but the unstable footing and short steep section make it more demanding than the distance suggests.

The basin is the attraction: a stream through an open meadow, golden larches in fall, and steep limestone walls with Mount Arethusa, Little Arethusa and Storm Mountain above them. Wildflowers are reported in summer; larch color usually arrives in mid to late September, though the exact week changes each year. For a photo, keep the creek in the foreground and frame the peaks through the meadow rather than shooting only the rock wall.

The talus also holds fossils. The limestone belongs to the Rundle Group, rock laid down in a warm, shallow sea about 340 million years ago and later shifted along the Rundle Thrust. Coral forms and shell fossils have been reported in the rockfall. Look closely, but leave every fossil where it is; collecting is prohibited in provincial parks.

There are no confirmed washrooms, bins or drinking water at the pullout; a portable toilet has been mentioned by visitors, but it is not something to count on. Use facilities at Ptarmigan Cirque before driving south and bring your own water. The small gravel area can fill during larch season, so an early start helps. Highway 40 closes each winter from December 1 through June 14, and a Kananaskis Conservation Pass is required for vehicles using the area. Dogs are allowed on a leash no longer than 2 metres.