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1986 Map of Madison Arm

Name: 1986 Topographic Map of Madison Arm
Creator: U.S. Geological Survey
Published: 1986
License: https://creativecommons.org/publicdomain/mark/1.0/

USGS Topo · Published 1986

About this map

Hebgen Lake and its prominent Madison Arm dominate the high-altitude topography of this Montana-Idaho border region during the mid-1980s. The landscape is defined by the convergence of the Gallatin National Forest and Targhee National Forest, split by the Continental Divide as it winds through Gallatin and Fremont Counties. The map records the hydraulic complex of the South Fork Madison River and the sweeping Madison Valley, where the terrain transitions from the water's edge to the mountain crests.

Transportation and infrastructure are captured in specific detail, including the Yellowstone Airport near the eastern margin and an Old Railroad Grade that traces the historical movement through the timber. Remote points of interest like the Basin Cabin and Black Sand Spring provide exact locations for specific local landmarks, while smaller drainages like Denny Creek and Buttermilk Creek illustrate the fine-grained hydrology of the basin before any modern development altered the drainage patterns.