Wind River Arboretum, Research arboretum in Skamania County, United States.

Wind River Arboretum is a research arboretum in the Gifford Pinchot National Forest near Carson, Washington, and the oldest in the Pacific Northwest. Foresters planted 165 tree species from temperate and subtropical zones to compare them with native Coast Douglas-fir and Western Hemlock; most non-native trees have died. A section of the fallen Mineral Tree, recognized in 2025 as the tallest Douglas fir recorded in the state, is kept here.

Thornton T. Munger of the United States Forest Service established the arboretum in 1912 to find the best trees for commercial use. Foresters planted species from temperate and subtropical zones and compared them with native Pacific Northwest trees. After more than 90 years and 165 species tested, the conclusion was that native species suit the local environment best, and most non-native trees have died.

The arboretum's name comes from the Wind River, whose valley holds old-growth Coast Douglas-fir and Western Hemlock, much of it over 400 years old. Foresters planted about 165 species from temperate and subtropical zones beside these natives; most non-natives died, and the surviving comparison plots show which trees failed. A section of the fallen Mineral Tree, recognized in 2025 as the tallest Douglas fir recorded in Washington, was given to the arboretum.

The arboretum lies within the Wind River Experimental Forest in the Gifford Pinchot National Forest near Carson. The sources give no visitor facilities, opening times or trails, so plan to explore the surrounding old-growth stands of Coast Douglas-fir and Western Hemlock on foot.

Decades of research here revealed that native tree species thrive far better than imported varieties from other regions. Many of the transplanted trees failed to survive over the years, while local species continued to flourish.