Carthew-Alderson Trail

Start at Cameron Lake Day Use Area, on the left as you face the lake. Long switchbacks climb through forest toward Summit Lake; the grade is steady rather than brutal at first, and the route opens up as you gain height. Summit Lake is the first big pause, but it is also a junction: Boundary Creek Trail branches toward Boundary Bay and the Lakeshore Trail. Stay on Carthew-Alderson and climb toward the high saddle.

The climbing gets steeper above Summit Lake, and the trees give way to open alpine slopes and loose rock. Parks Canada calls this high point “the Summit,” but it is a saddle between Mount Carthew and Mount Alderson, not a mountain top. From here you can look down on the Carthew Lakes, back across the Waterton Valley and out toward the prairie. The route is exposed here, so wind, lingering snow and poor visibility matter more than they do in the forest. A side path climbs to a higher viewpoint, but it adds effort and more exposure; the through-route has plenty of view already. For a photo, frame the lakes below the shale ridge with the valley beyond so the drop has some scale.

The trail drops steeply from the saddle onto red-pink shale and scree. It is loose underfoot, and the upper lake can hold snow well into summer. Keep to the obvious path around the lakes rather than cutting across the slope. Small cascades join the upper and middle lakes, and the mix of pink rock, alpine shrubs and water is the most distinctive stretch of the hike. The route passes Summit Lake and the Carthew Lakes; it is worth slowing down here before the next steep descent.

Beyond the Carthew basin, the route drops through a narrow valley below Mount Carthew to deep-blue Alderson Lake, tucked under Mount Alderson’s cliffs. There is a backcountry campground on the far shore; reserve a site if you want to stay overnight. From the lake, follow the trail down along Carthew Creek and then toward Cameron Creek. The lower descent is easier walking, with stretches of forest, small cascades and views back toward the townsite. The 2017 Kenow wildfire changed parts of these slopes; burned trees now stand among regrowth, berry bushes and wildflowers. Cameron Falls is the townside finish.

Walk from Cameron Lake down to town if you can arrange it. The trail is point-to-point, so take a shuttle to the lake or stage vehicles at both ends; check current shuttle times and rates before you go. Bring your own food and water for the day. A Parks Canada entry pass is required, and dogs must stay on leash; follow any posted area restrictions. Bears are reported along this route, so carry bear spray where you can reach it. The backcountry reservation applies if you camp at Alderson Lake, not just because you are hiking through.