The east-west range of Douglas-fir is the greatest of any commercial conifer of western North America.
Its native range is from central British Columbia, south along the Pacific Coast Ranges for about 1,367 miles south, representing the range of the typical coastal or green variety, menziesii. The longer arm stretches along the Rocky Mountains into the mountains of central Mexico over a distance of nearly 2,796 miles, comprising the range of the other recognized variety, glauca - Rocky Mountain or blue.
Nearly pure stands of Douglas-fir continue south from their northern limit on Vancouver Island through western Washington, Oregon, and the Klamath and Coast Ranges of northern California as far as the Santa Cruz Mountains.
In the Sierra Nevada, Douglas-fir is a common part of the mixed conifer forest as far south as the Yosemite region. The range of Douglas-fir is fairly continuous through northern Idaho, western Montana, and northwestern Wyoming. Several outliers are present in Alberta and the eastern-central parts of Montana and Wyoming, the largest being in the Bighorn Mountains of Wyoming. In northeastern Oregon, and from southern Idaho south through the mountains of Utah, Nevada, Colorado, New Mexico, Arizona, extreme western Texas, and northern Mexico.
Inter-mountain Forest Zones
Forest Types of North America
The Great American Conifer Forest