Weir Creek Roadless Area is 22,000 acres, with Highway 12 providing the southern boundary, and the Lolo Motorway creating the northern margin. The interior is guarded, traversed by only two short, low-standard trails. The country is forged by steep river breaklands, undulating sharply from 3,000 feet at Highway 12 to 7,000 feet along the Lolo Motorway. In addition to the two major streams for which it is named, numerous other first and second-order streams drain directly into the Lochsa River, and at the head of Post Office Creek lies a large cirque basin with two glassy lakes. The underlying Cretaceous Idaho Batholith gives rise to prominent rock outcroppings and geologic formations such as the weathered column known as “Devil’s Chair” along the Lolo Motorway.
The lower half of the area, generally below 5,000 feet, is made up of cedar-hemlock-pine ecosystem, while the higher elevations are principally western spruce-fir forest. Large forest fires in the early 1900s had a significant influence on the present vegetation, with much of the area especially along south and west portions consisting of brush fields. Unburned areas and land that has regenerated are comprised of a wide variety of western red cedar and grand fir habitat types in the lower end and subalpine fir types at higher gradients. Elk, deer, bears, and moose are the most common large mammals. Rocky Mountain goats were mentioned in the journals of Lewis & Clark and some still exist near the upper end of the drainage. Gray wolf, wolverine, fisher, Columbia spotted frog, Coeur d’ Alene salamander, and western toad habitat overlaps this area. The streams are a critical environment for Summer Chinook, steelhead, Westslope – cutthroat, and Bull trout.
The steep, sloping terrain coupled with dense vegetation translates to a high level of seclusion within the cool, shady depths of the canopy. Hot springs, like those at Weir Creek, invite the explorer to soak in warm pools worn smooth over generations; a small border adjustment in the wilderness proposal would exclude this popular spot from designation because of extremely heavy use, but the remaining country is eligible for wilderness consideration. The Lolo Trail is a significant cultural heritage feature as a route for prehistoric indigenous travel, Lewis & Clark, and Chief Joseph’s band of non-treaty Nez Perce Indians. A .25 mile wide corridor within an unmarked boundary of the Middle Fork/Lochsa River runs the full length of the roadless area. This 500 acre corridor is supervised under a Special River Management Plan to emphasize the scenic values and ecological contributions of the river environment. In addition, a National Recreation Trail is also located within the corridor at Colgate Warm Springs salt lick. The compact size and absence of privately owned land makes Weir Creek a natural integration into an expansive self-managed landscape that would include the adjacent Fish – Hungery Creek, Weitas Creek, and Lochsa Face Roadless Areas.
Description of other Roadless Areas on the Nez Perce – Clearwater National Forests.
Weir Creek (Weir – Post Office)