Cooper River Trail

Alpine Lakes Wilderness, Washington

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Cooper River Trail


  • Salmon La Sac Forest Service Station.- Cooper River Trail
  • Following the signs to the summer trailhead.- Cooper River Trail
  • Continuing up the service road.- Cooper River Trail
  • Cooper River summer trailhead.- Cooper River Trail
  • Cooper River.- Cooper River Trail
  • An early portion of the Cooper River Trail.- Cooper River Trail
  • Red Mountain (5,722').- Cooper River Trail
  • Spotting an elk through the brush.- Cooper River Trail
  • Fir forest near the riverbank.- Cooper River Trail
  • Cooper Lake outlet from the bridge.- Cooper River Trail
  •  Looking down the river from the bridge.- Cooper River Trail
  • Cooper Lake from the north shore.- Cooper River Trail
  • Summer cabins on the lake.- Cooper River Trail
  • Forest Road 4616 along the Cooper River Trail.- Cooper River Trail
  • Old cedars (Thuja plicata).- Cooper River Trail
  • Cooper River.- Cooper River Trail
  • Trail through a small gulch.- Cooper River Trail
  • Wood-pecked fir bark.- Cooper River Trail
  •  Looking down the Cle Elum River from the bridge crossing.- Cooper River Trail
  • Views up the Cle Elum River from the bridge.- Cooper River Trail
  • - Cooper River Trail
Overview + Weather
Old-growth forest. Scenic rivers. Frozen lake.
Noisy snowmobile recreation areas nearby.
Alpine Lakes Wilderness, WA
Pets allowed: 
Groomed trail: 
Net Elevation Gain: 
400.00 ft (121.92 m)
Parking Pass: 
NW Forest Pass
Preferable Season(s):
Total Distance: 
11.00 mi (17.70 km)
Trail type: 
Trailhead Elevation: 
2,413.00 ft (735.48 m)
Typically multi-day: 
Current Local Weather:
Adventure Description

Adventure Description


Although this snowshoe and cross-country ski route's name suggests otherwise, the Cooper River Trail showcases the surrounding mossy, old-growth fir forests more than rivers. Provided you stay on course, the trail rolls gently along an occasionally steep valley wall and dips into small gulches. Taking your time to stay on the path really pays off, and it can greatly increase the likelihood that you will spot some of the abundant wildlife in the area.

The route departs from a winter turn-around area at the end of SR 903 N, which is also the entrance to the Salmon La Sac Sno-Park, a popular area among snowmobilers.  The initial 1.5 miles to the official Cooper Lake Trailhead is a well-signed, fairly flat trek along the edges of private property. Start by passing the Forest Service Station, then continue across a bridge over the Cle Elum River to the head of the Cooper River Valley. After traveling a short distance up the trail, you will pass high above the river and get a brief view of Red Mountain standing tall across the mouth of the valley. Wide trees and steep slopes form the scenery for the next 2.5 miles before the trail provides more level footing by dropping down near the river bank. The Cooper River headwaters soon become evident where Forest Road 4616 crosses a bridge over the Cooper Lake outlet. 

If you have the time, travel the extra 0.1 mile up the road to the Lake Shore Trail. Although snowmobiles can often be heard about the hills in the lake area, the north shore boasts perfect picnic accommodations and picturesque scenery toward Cooper Pass to the west.   

Note: Always check weather and avalanche conditions before traveling in the backcountry in the winter.

Recommended Gear

Before you head out on your next Mount Hood adventure, make sure you have the right gear! 

Here's a list of our go-to snowshoeing essentials to get you started:

Snowshoes: MSR Lightning Ascent Snowshoe

Cushioned, Made in USA, Ultralight, 98.8 oz

Men's • $299.95 • MSR | Amazon | Backcountry | REI

Women's • $299.95 • MSR | Amazon | Backcountry | REI

Jacket/Shell: Arc'teryx Zeta AR Jacket

Waterproof, Adjustable Drawcord Hem, Pit Zips, GORE-TEX

Men's • $431-475 • Arc'teryx | Amazon | Backcountry

Women's • $475 • Arc'teryx | Amazon | Backcountry

Pack: Mammut Nirvana Pro Pack 

35L, Carry-On Size, Hip Belt, Ice Axe / Pole Loops, Hydration Compatible

Standard Fit • $189.95-199.95 • Mammut | Amazon | Backcountry

Small Fit • $199.95 • Mammut | Amazon

Insulating Layer: Moosejaw Dequindre Down Jacket

Water-resistant, Insulated, Adjustable Drawcord Hem

Men's and Women's • $179

Poles: Black Diamond Traverse Pole 

Aluminum, Adjustable with Lever Lock System, 21 oz.

$79.95 • Black Diamond | Amazon | Backcountry | REI

Gloves: The North Face GORE-TEX Gloves

Waterproof, Adjustable, Insulated, GORE-TEX

Men's • $99.95-181.63 • The North Face | Amazon | Backcountry

Women's • $99.95-100.00 • The North Face | Backcountry

Boots: Vasque Snowblime UltraDry Boot

Waterproof, Cushioned, Insulated

Men's • $149.99 • Vasque | Amazon | Backcountry

Women's • $149.99 • Vasque | Amazon | Backcountry

Gaiters: Outdoor Research Verglas Gaiter 

Waterproof, Breathable, Lightweight, Abrasion-resistant

Men's • $41.32-65 • Outdoor Research | Amazon | Backcountry | REI

Women's • $49.95-65 • Outdoor Research | Amazon | Backcountry | REI

Backcountry Safety

Winter backcountry adventures can be dangerous outdoor activities that pose significant risks as conditions affecting safety (i.e. weather, snowpack stability, avalanche hazard) are constantly changing. Prior to engaging in these activities each individual should get the proper training to make safe decisions and be equipped to use avalanche safety resources and tools. Please visit our Backcountry Skiing and Avalanche Safety post to learn more.

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Nearby Camping + Lodging

(24 within a 30 mile radius)

Nearby Adventures

(114 within a 30 mile radius)

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