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Thornton Lakes

Fantastic backcountry campsites await at the stunningly-beautiful Thornton Lakes.

Hiking Difficult

15 km
1.1 km
1.1 km
4-5 hrs
Low Point
752 m
High Point
1.5 km
Thornton Lakes Map

The Thornton Lakes are suspended in a high-alpine valley below jagged, rocky mountain peaks. These crystal-clear lakes are a popular backpacking destination in North Cascades National Park, with beautiful campsites available near the shore of the lower lake.


The 9-mile round-trip route might not sound too long, but with about 3,500 vertical feet of elevation gain, it makes for a stiff but achievable day hike.

The hike to the lake starts off easy, following "a brushy old road grade for the first half of the trail with minimal elevation gain," according to PlanetWare.com.

Then, the route reaches a true trail and a real climb as it quickly begins ascending steeply up to a ridgeline, finishing with a series of steep switchbacks. On the ridge, you'll enjoy stunning views of the North Cascades, including Teebone Ridge, Skagit Valley, and Trapper Peak. If you take a right on top of the ridge, you can continue climbing to the summit of Trapper Peak.

Once you're done admiring the view, you'll drop down a steep half-mile to the lakes, where you'll find the campsites along the lakeshore. Note that a permit is required for overnight camping, but not for day hiking.

Sources: https://www.planetware.com/washington/top-rated-hikes-in-north-cascades-national-park-us-wa-130.htm https://www.earthtrekkers.com/best-hikes-in-north-cascades-national-park/



Hiking trails where obstacles such as rocks or roots are prevalent. Some obstacles can require care to step over or around. At times, the trail can be worn and eroded. The grade of the trail is generally quite steep, and can often lead to strenuous hiking.

Medium Exposure

2 out of 4

The trail contains some obstacles such as outcroppings and rock which could cause injury.


4 out of 4

In the high mountains or remote conditions, all individuals must be completely autonomous in every situation.

Best time to visit

between July and September


  • Alpine
  • Picturesque
  • Water features

Guidebooks in this area