Tumac Mountain & Twin Sisters Lakes

Hike to lakes or a mountain just south of Bumping Lake in the William O. Douglas Wilderness. It's up to 15.1 miles round trip and 2,400 feet of elevation gain.

Getting there

From SR 410, 19 miles east of Chinook Pass, turn south onto Bumping River Road (Forest Road 18). Continue on paved road for 11 miles. After 11 miles where the paved road turns right and heads toward Bumping River Damn, stay straight and drive on Forest Road 1800 for 2.6 miles. Then turn left onto Forest Road 1808 and follow until it ends at the trailhead and a small campground (4,300 ft).

On the Trail

Tumac Mountain

A moderate day hike on trail to the top of Tumac Mountain. It's 7.8 miles and 2,130 feet of elevation gain.

Twin Sisters Lakes

An easy day hike to and from South Twin Sisters Lakes. It's 5 miles round trip with 1,060 feet of elevation gain. You can also loop via the Indian Creek Trail.

Tumac Mountain & Twin Sisters Lakes Loop

Hike south past Twin Sisters Lakes and on to Tumac Mountain. Continue southwest to the Pacific Crest Trail (PCT), turn north on the PCT and follow it to the junction with the Twin Sisters Lakes Trail. Head back to the trailhead from here. It's 15.1 miles and 2,400 feet of elevation gain.

  • Suitable Activities: Backpacking, Day Hiking
  • Seasons: July, August, September, October
  • Weather: View weather forecast
  • Difficulty: Easy, Moderate
  • Length: 15.1 mi
  • Elevation Gain: 2,500 ft
  • 6,340 ft
  • Green Trails Goat Rocks William O Douglas Wilderness No. 303S
  • Trails Illustrated Goat Rocks, Norse Peak & William O. Douglas Wilderness Areas
  • Green Trails White Pass No. 303

Upcoming Activities

There are no activities scheduled at this location.

Trip Reports

This is a list of titles that represent the variations of trips you can take at this route/place. This includes side trips, extensions and peak combinations. Not seeing a title that fits your trip? Log in and send us updates, images, or resources.

  • Tumac Mountain
  • Twin Sisters Lakes
  • Tumac Mountain & Twin Sisters Lakes Loop

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