USGS Scientist Holding Leopard and Boreal Chorus Frog Larvae

USGS scientists collected amphibians as part of an effort to study if historic oil and gas production in the Williston Basin has affected amphibians in the Prairie Pothole Region. This photograph shows a larval leopard frog (bottom) and a larval boreal chorus frog (top) that are two of the amphibian grazers collected from a wetland near Lostwood National Wildlife Refuge, North Dakota.