1999. U.S. Geological Survey. This map layer includes the locations of over 500 majors dams in New York State. The information in the map layer was provided by the U.S. Army Cor...
1994. U.S. Geological Survey. This data set shows the 1991 and 1994 National Water-Quality Assessment (NAWQA) study units' major surface-water sampling sites. These sites are in...
2001. U.S. Geological Survey and Florida Caribbean Science Center. A small mollusk called the zebra mussel has been steadily invading America's rivers and lakes. Zebra mussels colonize water intake pipes and severe...