Hiking Project Logo

black Thornton Lakes

  4.6 ( 8 ) Favorite

Trail

9.5 mile 15.4 kilometer out and back
Difficult

Elevation

Ascent: 3,067' 935 m
Descent: -3,067' -935 m
High: 5,018' 1,530 m
Low: 2,499' 762 m

Grade

Avg Grade: 12% (7°)
Max Grade: 58% (30°)

Dogs

No Dogs
Driving directions Take a virtual tour
Zoom in to see details
Map Key

Trail shared by Sarah Baker

Weather

Getting forecast...

Current trail conditions

Unknown See History

Popular hikes nearby

Navigate on-trail with our free app

iOS App Store Android App Store

A pleasant, steep trail through dense forest to subalpine lakes in a beautiful mountain basin.

Sarah Baker

Features Birding · Lake · River/Creek · Swimming · Views · Wildflowers · Wildlife

Overview

The Thornton Lakes Trail is a nice day trip or overnight to a subalpine lake with views of the rugged North Cascades Peaks. Additionally, there are many opportunities for off-trail exploration in the area.

The first two miles of trail gently ascend an old road grade through new growth forest. Then, the trail trail climbs steadily upwards through mature hemlock forest until it reaches meadows and attains the ridge. The ridge offers spectacular views of Triumph Peak and lower Thornton Lake.

The short, steep trail down to lower Thornton Lake is often muddy and slippery. Be especially careful on the rock and floating-log scramble to cross the outlet of the lake and reach the camp.

Need to Know

A backcountry permit is required for all overnight stays in the national park. Camping in the Thornton Lakes area must be at a designated site. Permits are limited so make sure to check with a the local Rangers Station for permit availability.

Thornton Lake has three sites which are popular and fill quickly during busy periods. Camping is not allowed on the ridge above the Thornton Lakes, Trappers Peak, or at the second Thornton Lake. Climbers attempting Triumph Peak may obtain a permit to camp at the Triumph Col cross-country zone.

Description

The trail starts at Thornton Lakes Trailhead and follows an old road grade for 2.3 miles through a logging area from the 1960's, before the park was established. The trail is surrounded by a natural mix of Douglas-fir, Pacific silver fir, hemlock, cedar, alder, maples, and various shrubs that can prove bothersome.

At the third switchback, the trail steepens and continues to climb up many moderate to steep switchbacks. The trail ascends through forested slopes, through a wet meadow and over a creek before officially entering North Cascades National Park. At 4.5 miles, the trees thin, and the trail breaks out into meadows of heather and huckleberry and continues to climb to an open ridge. From the ridge, you get expansive views of Mt. Triumph, Teebone Ridge, and the Skagit Valley.

A scramble route leaves the main trail at the ridge and ascends steeply towards Trappers Peak. If you spend the night at Thornton Lakes, this can be a great extension of your trip. The views from Trappers Peak of the three Thornton Lakes and the rugged Picket Range are truly spectacular.

The main trail descends steeply for 0.6 miles down 500 ft along a lesser ridge with views of lower Thornton Lake and Triumph Peak beyond. Be careful crossing the lake outlet as the boulders and rocks can be wet and slippery! The maintained trail ends at lower Thornton Lake where there are 3 permit campsites and a compostable toilet.

From lower Thornton Lake there is a primitive climber's path that proceeds to the upper lakes and Triumph Col. The two lakes above are cupped in their own rocky basin, forming classic cirque lakes that were created by glaciers which carved the rock basin before retreating to where they are today.

Flora & Fauna

The trail offers a rich wildlife habitat. Keep an eye out for deer, bear, marmot, and birds. Hawks and eagles can be observed during autumn migration.

This ecosystem has very fragile vegetation. Make sure to avoid trampling vegetation by hiking and resting only on durable surfaces such as the trail, snow, or rocks.

Hiked this trail?

We need help with the following missing trail information:

History & Background

Is something wrong? Let us know. Have photos to share? Help fellow hikers know what's here.

Contacts

Rate This Featured Hike

Rate Quality


   Clear Rating

Rate Difficulty

Share This Hike

Check In

Check-Ins

Jun 27, 2019
Dennis Chan
9.5mi
Jul 22, 2018
Jessica S
Jul 11, 2018
Wendy Heil
Sep 17, 2017
Jodie Buckingham
Aug 23, 2017
Garret Bonnema
10.5mi — 5h 03m
Jun 10, 2017
Braden Barranco
Oct 6, 2012
Coniques X

Stewarded By


Trail Ratings

  4.6 from 8 votes

#1196

Overall
  4.6 from 8 votes
5 Star
75%
4 Star
13%
3 Star
13%
2 Star
0%
1 Star
0%
Featured Hike Rankings

#78

in Washington

#1,196

Overall
167 Views Last Month
2,590 Since Mar 1, 2016
Difficult Difficult

0%
0%
0%
43%
43%
14%

0 Comments

Hiking Project is part of the REI Co-op family,
where a life outdoors is a life well lived.

Shop REI Hiking