2020 Map of Powderhorn Gulch

About this map

High-country drainage patterns and public lands dominate this section of Salmon National Forest in Lemhi County. The terrain is defined by its namesake Powderhorn Gulch and the deeply cut Perk Canyon, which funnel seasonal runoff toward the broader valley floors. These systems feed into notable watercourses including Eighteenmile Cr, Clear Cr, and Tenmile Cr. The road network is sparse, consisting largely of unpaved access routes like Bull Cr Rd and Eighteen Mile Rd that follow the natural contours of the mountain foothills. This 2020 record illustrates the enduring isolation of this part of Idaho, where land management boundaries for the forest meet the open grazing and riparian corridors of the high desert basins, maintaining a landscape largely unchanged by modern development.