The Mineral Development Atlas (MDA) was a joint project by the United State Geological Survey (USGS), the United States Bureau of Mines (USBM), and the state surveys of Wisconsin, Illinois, and Iowa, and was launched in 1945 to gather information about mining and exploration in the lead-zinc district of the Upper Mississippi Valley. The Atlas consists of section maps at 1:2400 scale showing exploration and mining activity in the area. In 1960, when the USGS offices in Platteville, WI closed, the Atlas was distributed to the states. The Wisconsin portion covers primarily Grant, Iowa, and Lafayette Counties, and WGNHS is currently working towards making this part of the Atlas publicly available online. The Lafayette County portion of the Atlas contains these GIS layers: 460 section maps showing surface and sub-surface mining activity (compiled in 1 layer), surveyed workings, unsurveyed workings, lead diggings, and boreholes. Borehole metadata is incomplete at this time; To-From data will be added when completed. Logs for the approximately 16,700 boreholes are available as scanned PDFs, grouped by section. Item level metadata has been created for surveyed and unsurveyed workings, lead diggings (at or near the surface), and boreholes.
