Region
Virginia
West Virginia
5
Maryland
3
North Carolina
3
Appalachian Region
2
Barboursville Basin
2
Big Stone Gap
2
California
2
Chesapeake Bay (Md. and Va.)
2
Culpeper Basin (Va. and Md.)
2
Eastern Shore (Md. and Va.)
2
Fairfax County
2
Fredericksburg
2
Hopewell Region
2
Kentucky
2
North America
2
Pamunkey River Watershed
2
Piedmont
2
Prince William County
2
Rappahannock River
2
Rappahannock River Region
2
Stafford County
2
Appalachian Basin
1
Champlain Valley
1
Chesapeake Bay Region (Md. and Va.)
1
Colorado
1
Connecticut
1
Danville Basin
1
Dinwiddie County
1
Elizabeth Hartwell Mason Neck National Wildlife Refuge
1
Fredericksburg Region
1
Greensville County
1
Gunnison County
1
Konnarock Formation
1
Massachusetts
1
Minnesota
1
Montana
1
Mount Rogers Formation
1
New Kent County
1
New Mexico
1
Norfolk Region
1
Northampton County
1
Pocahontas County
1
Rhode Island
1
South Carolina
1
Sussex County
1
Taos County
1
United States
1
Washington (State)
1
Wise County
1
more ...