Alderson Lake

Why this hike

If you want one hike that delivers it all—high ridge, jewel-box lakes, and a finish right in town—the Alderson Lake segment of the Carthew–Alderson route is the move. It’s commonly done either as a shorter out-and-back to Alderson Lake or as part of the full Cameron Lake-to-town traverse that many consider one of the most beautiful days in Waterton. Expect big-mountain views and a satisfying lake stop that feels tailor-made for a long lunch break [adventurealberta.ca](https://adventurealberta.ca/carthew-alderson-hike/).

Route and distance

For an Alderson-only outing, plan roughly 8.6 miles round-trip (out-and-back on a portion of the Carthew–Alderson Trail), typically 4–6 hours depending on pace and conditions [adventurealberta.ca](https://adventurealberta.ca/carthew-alderson-hike/). If you want the classic experience, the full traverse runs about 12 miles (19–19.5 km) one-way from Cameron Lake to the Waterton townsite, passing the Carthew Lakes, a waterfall, and then Alderson Lake before descending to town [adventurealberta.ca](https://adventurealberta.ca/carthew-alderson-hike/) [travelyesplease.com](https://www.travelyesplease.com/travel-blog-waterton-lakes-national-park-itinerary/).

Scenery and geology

You’ll move from subalpine forest and meadows to a high ridge with sweeping views into both the Canadian and U.S. Rockies, then down through a chain of lakes—including Alderson in its steep-walled basin. The terrain features distinctive red argillite scree and talus that add a unique color palette to your photos [adventurealberta.ca](https://adventurealberta.ca/carthew-alderson-hike/). Portions of the route traverse post-wildfire forest, opening up long sightlines and changing the character of the hike compared to pre-fire trips [awalkandalark.com](https://www.awalkandalark.com/carthew-alderson-trail-waterton-lakes/). Keep an eye out for wildflowers in mid-summer and typical mountain wildlife like deer, birds of prey, and the occasional bear [parkscanadahistory.com](http://parkscanadahistory.com/publications/waterton/guide-e.pdf).

Difficulty and feel

Overall, this is a moderate-to-challenging mountain hike due to length, elevation, and some rocky, windy, and exposed sections on the ridge. Many hikers call it varied and never monotonous—forest, ridge, lake, then valley—though the lower valley descent back toward town can feel long, and in places late-season vegetation can brush the trail.

Best time to hike

Aim for late June through September. Snow can linger on the high sections into June, wildflowers peak in July and early August, and fall colors make September special. Ridge sections can be windy year-round; bring layers. Early and late season, check high-country snow conditions before committing [travelyesplease.com](https://www.travelyesplease.com/travel-blog-waterton-lakes-national-park-itinerary/).

Logistics and tips

• Easiest logistics: park in the Waterton townsite and ride the seasonal hiker shuttle to Cameron Lake, then hike back into town for the full traverse. It’s a true walk-to-dinner kind of day [adventurealberta.ca](https://adventurealberta.ca/carthew-alderson-hike/).
• For the Alderson Lake out-and-back, you’re simply sampling a portion of the same route; still start early and bring plenty of water and calories.
• Carry bear spray, make noise in brushy sections, and bring wind protection for the ridge. The route is well marked, but a map/GPS is smart in mountain weather [adventurealberta.ca](https://adventurealberta.ca/carthew-alderson-hike/) [parkscanadahistory.com](http://parkscanadahistory.com/publications/waterton/guide-e.pdf).

Bottom line

Alderson Lake is a worthy destination on a route with no dull moments. If you have the legs, do the full traverse; if not, the out-and-back to Alderson still gives you the ridge-and-lake highlights without shuttle logistics [adventurealberta.ca](https://adventurealberta.ca/carthew-alderson-hike/) [awalkandalark.com](https://www.awalkandalark.com/carthew-alderson-trail-waterton-lakes/).