Carthew-Alderson Trail

Why this hike

This is the park’s signature point‑to‑point traverse: a full‑value day that strings together an alpine ridge, a chain of turquoise lakes, a dramatic waterfall crossing, and a satisfying walk right into town. It’s long, scenic, and varied—the kind of route you’ll remember. Expect a challenging day with sustained climbing, big views, and a very long descent.

The experience, step by step

Most hikers start at Cameron Lake and finish in the Waterton townsite near Cameron Falls. From Cameron Lake, the trail climbs steadily through forest to Summit Lake, then tackles a gritty scree slope onto Carthew Ridge—the money views. From the ridge you’ll stare across to peaks in Glacier National Park and down to the Carthew Lakes cupped between Mount Carthew and Mount Alderson. The trail then drops to the lakes (great lunch spot), threads along shorelines and creeks, and meets a tall waterfall where you cross at a brief break in the flow. A short spur leads to Alderson Lake beneath steep stone walls. From there, the descent continues through valley forest, following Carthew Creek to Cameron Falls and straight into town.

Stats and difficulty

Plan for 11.6 miles (18.7 km) one way, typically 7–9 hours depending on breaks and photo stops. You’ll gain over 650 m (then lose much more), and upper sections are rocky, exposed, and windy. The exit through forest can feel long and overgrown in places—save a snack for this stretch.

Scenery, geology, and what to look for

You’ll move through a sampler of Waterton landscapes: subalpine forest and meadows, argillite scree and layered red rock on the ridge, and glacially carved basins holding those clear blue lakes. Watch for ripple marks in red stone and mud cracks in grey‑green rock—clues to ancient seabeds now lifted into mountains. The Carthew basin and Alderson valley are classic U‑shaped glacial terrain.

Season and best time to hike

Best window is late June through September. Snow can linger on the ridge and around the Carthew Lakes into early summer, making traverses slippery or impassable, and it’s not a good choice outside the summer–fall season due to snow and avalanche risk. Start early for calmer winds and more solitude on the ridge; midday can be windy and chilly even in summer. Book the morning shuttle when possible and bring layers.

Logistics, tips, and good‑to‑know

• Route is point‑to‑point. Most people ride a hiker shuttle from town to Cameron Lake, then hike back to their car or lodging in town—easiest logistics by far.
• Water is present at lakes/creeks but not always convenient; carry enough and a filter. Upper sections are dry and exposed.
• Be bear‑aware in forests and berry patches; carry spray and make noise.
• Day hiking requires only a park entry pass; overnighting at Alderson Lake’s designated camp requires a backcountry reservation.

Bottom line

If you want one big day that captures the park’s essence—ridges, lakes, waterfalls, and a stroll into town—this is it. The ridge and lakes are world‑class; just know the final forested miles can drag after such a high‑alpine start.