| Thornton Lakes | |
| Coords: | 48.6878°N -121.3325°W[1] |
| Type: | Cirque Lakes |
| Outflow: | Thornton Creek |
| Basin Countries: | United States |
| Length: | 800yd |
| Width: | 400yd |
| Elevation: | 4708feet |
| Pushpin Map: | Washington#USA |
| Pushpin Map Alt: | Location of Thornton Lakes in Washington, USA. |
Thornton Lakes are located in North Cascades National Park, in the U. S. state of Washington.[2] These paternoster lakes consist of three lakes located 1miles1.75miles southeast of Mount Triumph. Thornton Lakes can be accessed on foot from a trailhead in Ross Lake National Recreation Area. The hike of 5.2miles includes a 2400feet altitude gain and a 500feet descent to Lower Thornton Lake.[3] Two other lakes lie above the first one, unofficially named Middle and Upper Thornton Lakes. A designated backcountry camping zone is located at Lower Thornton Lake.[4]