USGS Water Science Centers are located in each state.
Photo Gallery for Clarke County, Virginia
Clarke
County
Photo Gallery
Geology
FILE: geol14.jpg
DESCRIPTION:
Swallet hole along Dry Marsh Run
just north of Rt. 7. Flow in Dry Marsh Run is captured by
this swallet hole. Once the underlying voids are
completely saturated, flow in Dry Marsh Run continues downstream (to
the right in photograph). Same swallet hole as shown in
previous photograph.