USGS geologist approaches helicopter with samples

USGS geologist George Case approaches an R66 helicopter with samples collected from mineralized rocks near the Groundhog Basin Ag-Sn-Pb-Zn deposit. Field work was conducted at the headwaters of Porterfield Creek in the Stikine River corridor for the Transboundary Waters Project. The purpose of this work is to understand the geochemistry, mineralization, and distribution of the rocks that contribute to the chemistry of streams in the Stikine River corridor.