Reed Lewis, PG // Idaho Geological Survey

Geologic Mapping as It Applies to Mineral Exploration in Idaho

The Idaho Geological Survey has approximately 40 percent of the state covered by modern (digital) geologic maps. Funding is from federal, state, and industry sources, with most coming from the United States Geological Survey STATEMAP program. Four areas have significant exploration potential and have been the focus of 1:24,000-scale mapping (Elk City, Salmon, Stibnite, and De Lamar). Mapping west of Salmon has highlighted the importance of NNE faults as regional controls to gold mineralization, like those found at Stibnite and Elk City. State geological surveys fill a niche, particularly since the USGS mapping efforts are now limited.

About the Presenter

Reed Lewis has worked as a field geologist for the Idaho Geological Survey the past 22 years and has previous experience with the United States Geological Survey, including gold exploration with the USGS mission in Saudi Arabia. He has spent 40 field seasons in the mountains of Idaho and has authored or co-authored over 100 geologic maps, including the 2012 State Geologic Map. Reed also leads the effort at the Idaho Geological Survey to preserve and disseminate mining-related documents and maps via the website.


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