Trails for everyone, forever

Home Go Hiking Hiking Guide Thornton Lakes and Trappers Peak

Thornton Lakes and Trappers Peak

North Cascades > North Cascades Highway - Hwy 20
48.6537, -121.3242 Map & Directions
9.7 miles, roundtrip
Elevation Gain
3,789 feet
Highest Point
5,832 feet
Calculated Difficulty About Calculated Difficulty
Thornton Lakes and Trappers Peak. Photo by Day Hike.
  • Mountain views
  • Dogs not allowed
  • Summits
  • Lakes
Saved to My Backpack

Incredible views and beautiful alpine lakes are your reward if you can ascend this steep trail in the North Cascades. At the top, you can choose between taking in sweeping panoramic views of North Cascades National Park and the Pickets Range, or relaxing near the lowest of the Thornton Lakes, both of which make a rewarding destination. Continue reading

4.40 out of 5

(30 votes) Log in to rate

Hiking Thornton Lakes and Trappers Peak

Trappers Peak embodies the ruggedness and remoteness of the North Cascades. While the trail will make you work, the reward at the end is well worth the sweat. When you reach the lowest of the Thornton Lakes you’ll be faced with a decision: relax near the alpine waters, or scramble the rocky ridge that leads to Trappers Peak. Either way, you can’t go wrong. Keep in mind, if you want to overnight here, you'll need a backcountry permit from the ranger station in Marblemount.

The trail starts modestly, traversing the hillside through the forest and crossing a couple creeks with minimal elevation gain. Look closely and you’ll notice remnants of the decommissioned logging road you’re hiking on as you ramble along the first two miles. When you reach the end of the road, the trail will start to your left and begin to gain elevation. This section switchbacks through dense forest, and careful footing is needed to avoid the numerous roots that protrude into the trail.

At roughly mile four you’ll enter North Cascades National Park, where the trail will continue to climb until you reach a signed junction, about 4.2 miles in and 2,673 feet of elevation gain from the trailhead. Here you’ll need to decide if you want to spend some time by the lake, or continue ascending for sweeping panoramic views.

If you choose the lake, head left at the junction and travel downhill for 0.4 miles. This steep, and potentially very muddy trail, has spots of exposure, while also losing over 600 feet in elevation to reach the first of the three lakes. Accessing the second and third Thornton Lakes requires some scrambling along a climber's path through heavy brush.

If you decide to scramble the peak, take the right fork and get ready to gain some more elevation. The scramble to Trappers Peak will take you almost 1,000 feet higher in less than a mile before you can enjoy the views.

The trail to the peak is rugged, and at times requires the use of your hands to assist the climb. There isn’t much to speak of in exposure, but use careful footing, as there are sections where taking a fall could mean tumbling downhill a good ways.

As you reach the top, just under 6,000 feet, you’ll be treated to sweeping views of a number of North Cascades gems. In front of you, the Picket Range, with spiny, dagger-like peaks and dramatic glaciers. To the west, Mount Triumph looms above and the upper Thornton Lakes are visible down below. Turning around, you’ll find incredible views of the Skagit River and farmlands stretching as far as you can see, and the town of Newhalem can be spotted nestled alongside Highway 20.

WTA Pro Tip: A backcountry permit is required to camp here. These are available from the ranger station in Marblemount before you begin your hike and are $26.

Toilet Information

  • No toilet at trailhead

More information about toilets

Hike Description Written by
Erika Haugen-Goodman, WTA Staff

Thornton Lakes and Trappers Peak

Map & Directions

Co-ordinates: 48.6537, -121.3242 Open in Google Maps

Before You Go

A $26 backcountry permit is required to camp overnight in the North Cascades National Park Service Complex (incl. Ross Lake National Rec Area and Lake Chelan National Rec Area). Permits must be picked up in person at the Wilderness Information Center in Marblemount. See the National Park Service website for more information.

See weather forecast

WTA Pro Tip: Save a copy of our directions before you leave! App-based driving directions aren't always accurate and data connections may be unreliable as you drive to the trailhead.

Getting There

From Marblemount, drive Highway 20 (also known as the North Cascades Highway) east for 11 miles. Then turn left onto Thornton Lakes Road between mileposts 117 and 118. Proceed down this sometimes rough gravel road, gaining over 2000 feet, for about five miles to the trailhead at the road's end.

More Hike Details


North Cascades > North Cascades Highway - Hwy 20

North Cascades National Park

Guidebooks & Maps

Day Hiking: North Cascades (Romano - Mountaineers Books)

Green Trails Marblemount No. 47

You can improve or add to this guidebook entry!

Thornton Lakes and Trappers Peak

224 Trip Reports

Hiked here recently?

Submit a trip report!
Trip Reports