2024 Map of Madison Arm

About this map

Hebgen Lake and its distinctive Madison Arm dominate the northern landscape of this Gallatin County survey, where the South Fork Madison River feeds into the reservoir. The terrain is defined by the high elevations of the Henrys Lake Mountains and the Continental Divide, which marks the border between Montana and Idaho. This high-country wilderness is managed across the Gallatin National Forest and Targhee National Forest, showcasing a complex network of forest roads and trails like the Continental Divide National Scenic Trail and Madison Cream Divide Trail. In the lower reaches of the Madison Valley, infrastructure such as the Yellowstone Airport and various ranch sites including Deep Well Ranch suggest the area's development for both regional transport and seasonal recreation. Numerous water sources, including Black Sand Spring and Beaver Ponds, dot the drainages of Buttermilk Creek and Denny Creek.