2002. U.S. Geological Survey. This Butterfly Occurrence Database portrays the occurrence of butterflies in counties in New York State. Butterfly occurrence data are cumulative, ...
2001. U.S. Geological Survey. The National Land Cover Database 2001 tree canopy layer was produced through a cooperative project conducted by the Multi-Resolution Land Character...
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...