Crypt Lake

• Length: 8.7 km/5.4 miles (3–4 hours) one-way
• Elevation gain: 680 meters/2,230 feet
• Rating: moderate/difficult
• Trailhead: Crypt Landing; access is by boat. The Crypt Lake Shuttle (403/859-2362; June–Sept.; $14 round-trip) leaves the marina daily at 9 a.m. and 10 a.m. for Crypt Landing; return trips depart at 4 p.m. and 5:30 p.m.

This is one of the most spectacular day hikes in Canada. Access to the trailhead on the eastern side of Upper Waterton Lake is by boat. The trail switchbacks for 2.5 km (1.6 miles) past a series of waterfalls and continues steeply up to a small green lake before reaching a campground. The final ascent to Crypt Lake from the campground causes the most problems, especially for those who suffer from claustrophobia or acrophobia. A ladder on the cliff face leads into a natural tunnel that you must crawl through on your hands and knees. The next part of the trail is along a narrow precipice with a cable for support. The lake at the end of the trail, nestled in a hanging valley, is no disappointment. Its dark green waters are rarely free of floating ice, and the steep walls of the cirque rise more than 500 meters (1,640 feet) above the lake on three sides. The international boundary is at the southern end of the lake. A good way to avoid the crowds on this trail is to camp at the dock and set out before the first boat arrives in the morning.