Three Isle Lake

Overview

A Kananaskis classic with variety: an easy lakeshore warm‑up, then a steep headwall to a secluded alpine basin. It’s 10.2 km one way (about 6.3 miles) from North Interlakes Day Use to Three Isle Lake, with roughly 580 m of elevation gain. Most hikers treat it as a 20–21 km out-and-back (about 12.7 miles total). Alberta Parks rates it Difficult—and that headwall earns the grade.

Route Snapshot

Follow the north shore of Upper Kananaskis Lake from the trailhead, joining the Upper Lake Circuit. Key waypoints: Upper Lake Connector around 2.2 km, Invincible Creek at ~3.8 km (bike turnaround), and Forks Backcountry Campground near 7.1 km—your last mellow breather. Past Forks, the trail steepens to a stair section with a fixed chain and some loose rock and mild exposure; take special care if it’s wet or icy. Crest the headwall and the grade eases into Three Isle Lake’s basin and campground.

What It Feels Like

The approach is scenic—and often busy—along the lakeshore. After Forks the vibe flips to sustained effort. The chain-and-stairs headwall is memorable but manageable for fit hikers; it’s the crux on the descent when gravel or ice stacks the odds. The payoff is a rugged cirque lake with big surrounding peaks. Strong legs can tack on South Kananaskis Pass (about 2 km farther) or continue to Beatty Lake for a bigger day.

Best Times to Hike

Prime season runs mid/late June through October; expect lingering snow early and late season, especially on the headwall. As of December 2, 2025, plan for full winter conditions. Campgrounds are closed December 1–June 14 at Forks and December 1–June 23 at Three Isle Lake. For a gentler day in shoulder seasons, stick to the Upper Kananaskis Lake section before the headwall.

Logistics, Rules, and Camping

A Kananaskis Conservation Pass is required to park. Bikes and e-bikes are allowed only to Invincible Creek (~3.8 km); lock up there. Dogs are permitted but must be leashed. Group size limit is 15. Three Isle Lake Backcountry Campground sits about 10.3 km from the trailhead and has 16 tent sites, pit/vault toilets, and secure food lockers; no fires. Reservations are required (bookable 90 days out), with a maximum of 6 people and 1 tent per site during the operating season (typically late June to late November).

Safety and Nature Notes

This is prime bear country—carry spray, make noise, and store food properly. Expect limited cell coverage and fast-changing mountain weather. Early/late season traction (microspikes) and trekking poles are very helpful on the headwall. You’ll move from subalpine forest to alpine rock and meadows; watch for pikas and marmots near treeline and keep an eye out for larger wildlife like bears, elk, moose, and bighorn sheep.