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.
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.