2020 Map of Greenhorn Mountain

About this map

Marysville sits at the northern edge of this high-country landscape, where the legacy of mining and mountain transit is etched into the terrain of Helena National Forest. The geography is defined by the Continental Divide, which is traversed by the Continental Divide National Scenic Trail. Near the center of the map, Bald Butte and Drumlummon Hill overlook a network of gulches—including American Gulch and Ottawa Gulch—that hint at the area's gold-seeking history. To the south, the infrastructure of the Continental Divide crossing becomes more pronounced. Mullan Pass and the nearby Mullan Tunnel serve as critical transit points through the mountains, connecting the drainage of Austin Creek with the southern settlement of Blossburg. This area illustrates the late-twentieth and early-twenty-first-century management of public lands, balancing historic trail access with forestry roads like National Forest Development Road 4105.