Alderson Lake

Overview

Alderson Lake is a remote, aquamarine alpine lake tucked under the towering cliffs of Mount Alderson. It’s a classic glacial cirque lake—clear, cold, and dramatic—and one of the quiet rewards along the Carthew–Alderson traverse.

Getting There

Most hikers reach the lake via the Carthew–Alderson Trail, typically riding a shuttle to Cameron Lake and hiking back toward town so most of the big elevation is front‑loaded. Expect a difficult day: plan for sustained alpine travel, around 580 m of gain, and 5–6 hours one way. The lake itself sits a short spur off the main trail.

Why It’s Special

You get the whole alpine package: hanging valleys, a string of lakes, and broad ridge views on the way in, then this turquoise bowl cradled beneath sheer walls. The surrounding red‑pink bands come from argillite—iron‑rich sedimentary rock that adds color to the basin.

Landscape & Fire History

Parts of the approach pass through a burn area from a recent major wildfire. It can feel stark, but the open slopes boost the views and showcase regrowth.

Wildlife

Keep your eyes up on the cliffs and open slopes—hikers report bighorn sheep, marmots, and occasional mountain goats. Around the lake and trail, sightings have included bald eagles, mule deer, and, at times, black bears. Carry bear spray and follow food‑storage rules.

Camping & Facilities

There’s a designated backcountry campground by the lake with tent pads, food‑storage infrastructure, and a vault toilet. Water comes from the lake—filter or treat it. Anglers can fish here with a valid Waterton fishing license.

Best Time to Visit

Prime season is July–September, when snow patches are least likely (though they can linger). Start early for steadier light, fewer people on the traverse, and to dodge afternoon wind or storms. Midday brings the brightest turquoise tones on the water; late afternoon softens the light on the cliffs.

Good to Know

• Expect a chilly but swimmable lake on hot days; keep water‑collection spots clear of swimmers if you’re filtering.
• Trekking poles help on the steeper, sometimes snowy or rubbly sections.
• This is a remote setting—no services beyond the basic backcountry setup.