2011 Map of Porphyry Reef

About this map

Teton Pass and Sun River Pass mark the high drainage divides of this Montana wilderness, where the headwaters of several major river systems originate. The landscape is defined by massive geological formations like Porphyry Reef and Washboard Reef, which run alongside high-elevation meadows including Grizzly Park and McDonald Park. This 2011 survey captures the complex drainage patterns of the North Fork Sun River and its numerous tributaries such as Seven-Up Creek and McDonald Creek. The area is devoid of modern settlements, showing instead a network of natural landmarks and ridges, from Corrugate Ridge in the north to Wapiti Ridge in the south, preserving the character of the Flathead County backcountry as it appeared early in the twenty-first century.