One of the great Canadian hikes I’ve done is the Carthew Alderson Trail in Waterton Lakes National Park. It’s a beautiful hike with varied and outstanding scenery.
You’ll see mountains, glaciers, and five high alpine lakes. Throw in wildflowers in season, marmots and mountain goats, and possibly even a bear and you can understand why the Carthew Alderson trail is one of the best hikes in Waterton Lakes National Park.
The Carthew Alderson trail is best done as one way hike starting at Cameron Lake at the end of the Akamina Parkway and finishing at the Waterton Townsite by picturesque Cameron Falls.
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Carthew Alderson trail hike summary
Distance: 20.1 km or 12.5 miles one way with the help of a hiker shuttle.
Elevation gain: 651 m or 2,135 feet and an elevation loss of 1,016 m or 3,332 feet IF you start at Cameron Lake.
Time needed: Allow 5.5 – 7 hours one way.
Level of difficulty: A moderate to difficult hike, mostly on account of its length. This is not a family-friendly hike. Save it for kids that are 12 and older and are regular hikers.
Permit: You will need to purchase a park pass to enter Waterton Lakes National Park. There are daily passes but the best value is the Discovery Pass – good for a year across Canada.
Is there a shuttle to the Carthew Alderson trailhead?
You are able to shuttle from the Waterton townsite to Cameron Lake (a gorgeous start to the day) at the end of the Akamina Parkway.
This is where you pick up the one-way 20 km Carthew Alderson trail. Follow it right back to your car at the Waterton Townsite. Book a seat with the Tamarack Hiker Shuttle. The shuttle is pet-friendly.
The shuttle leaves early in the morning so you have plenty of time to do the hike during daylight hours.
You certainly don’t have to take the shuttle, but it wouldn’t be a lot of fun to start at the Waterton Townsite. You gain 1016 m to reach the Carthew Summit by starting in town. But by starting at Cameron Lake, you gain a modest 651 m. Almost all hikers start at Cameron Lake!
Carthew Alderson trailhead location
To find the Carthew Alderson trailhead you have to hike past the boat rental office, cross the bridge and look for the sign.
What is the best time to do the Carthew Alderson trail?
Plan to do the hike is from July until the snow starts to fly in early October. That’s when the shuttle stops running.
The hike to Carthew Summit
It’s easy to find the trailhead – and with all sorts of hikers disgorging from the shuttle bus, you’ll have company at least for a while.
Follow the trail, first on a boardwalk and the through forest as it switchbacks gradually for 4 km to Summit Lake. From there you get views of glaciers off in the distance. Don’t waste too much time at this lake though because the good stuff lies ahead.
Follow the sign, continuing up through the forest to reach tree line. The trail as you can see in one of the photos below follows the curve of the cirque on a scree-lined path. This part of the trail could be stinking hot in the summer as the heat gets reflected back at you. Drink a lot!
Reach Carthew Summit – a pass and not a real summit and enjoy the panoramic views from the prairies to Glacier National Park. When we were there it was cold and windy so be sure you’ve packed some extra layers. There is the option to continue to the Carthew Summit Overlook or even climb Mount Carthew,
From Summit Lake to the Carthew Lakes it’s 6 km.
Carthew Summit option
From the Carthew Summit, there is the option to hike 800 m to reach the Carthew Summit Overlook.
From the vantage point it affords, you will enjoy spectacular views of Glacier National Park in Montana. A rare few may choose to continue to the third highest peak in Waterton Lakes National Park – the summit of Mount Carthew topping out at an elevation pf 2,618 metres or 8,589 feet.
The descent to the Carthew Lakes
Once you crest the pass you head down, steeply at times, through a barren landscape of rock but the Carthew Lakes beckon in the distance.
Even in September when we did it there were snow patches. If you’re hiking earlier in the season, consider taking hiking poles so you don’t slip.
The hiking through this part of the Carthew Alderson trail is fabulous. I didn’t want it to end.
It would be easy to spend some time at the Carthew Lakes just admiring the scenery of the hanging valley.
Once you’re ready to leave, continue along the northeast side of the lake. Pass a second, larger lake – that boasts a little more in the way of wildflowers and re-enter stunted forest, just above the Alderson Lake cirque. Continue descending towards Alderson Lake – but on the way look for mountain goats on the steep cliffs above the lake.
Don’t forget to turn around every so often as the views are equally glorious looking back. This was one of my favourite sections on the Carthew Alderson trail.
Carthew Alderson Trail: the hike to Alderson Lake
On the way to Alderson Lake we passed outcrops with stromatolites – ancient algal mounds and some of the earliest life forms. It would be easy to mistake them for lichen if you didn’t know what you were looking for.
It’s only 2 km from Carthew Lakes to Alderson Lakes and they pass all too quickly.
We stopped to have lunch above Alderson Lake and were treated to the escapades of a few mountain goats eating and hopping on the cliffs at least 1,000 feet above the lake. I couldn’t get over the steepness of the slopes they were on.
Alderson Lake to Waterton Village
It’s possible to camp at Alderson Lake but not at the Carthew Lakes.
From Alderson Lake you head back into the woods on the Carthew Alderson trail for the final 7 km. This part of the trail turned out to be more interesting than I thought it would d be with plenty of peek-a-boo views and lots of wildflowers to stop and admire.
Close to the end of the Carthew Alderson trail, you reach beautiful Cameron Falls and you can see the Waterton Townsite off in the distance. In no time you’ll be back at your car, ready for a cold drink and a hearty meal.
Location map of the Carthew Alderson Trail
Where to stay in Waterton Lakes National Park
There is a wide range of accommodation options in Waterton from camping in town, backcountry camping and the large Prince of Wales Hotel.
Be sure to reserve well in advance, especially for weekends. Online reservations open in the winter for camping.