A brief tour of regional aquifers
Maps of major aquifers by rock/sediment type
California's Central Valley (an alluvial basin)
Great Basin (more alluvial basins)
Dakota Sandstone (part of the Colorado Plateau)
water level declines in the High Plains aquifer
Edwards Aquifer (within non-glaciated central region)
Piedmont and Blue Ridge Section
Crystalline PC & Northeastern Appalachians (Northeast and Superior Uplands)
Alluvial Valleys (distributed throughout the US)
Find lots more information via the Ground Water Atlas of the US
For a summary of Wisconsin's groundwater resources, the DNR has a good on-line publication
