Wild Wonders of Europe / Zupanc / River Lepenjica, with a pothole in rock, Triglav National Park, Slovenia, June 2009

Jim Brandenburg / Farmlands encroaching on prairie potholes, North Dakota

Floris van Breugel / A lichen covered wall of eroded basalt columns along the side Potholes Coulee near Ancient Lakes region, Washington, USA, April

Doug Wechsler / Pothole in the Fiery Furnace canyons, Arches National Park, Utah, USA, June

Wild Wonders of Europe / Zupanc / Pothole in rock next to the River Lepenjica, Triglav National Park, Slovenia, June 2009

Shattil & Rozinski / Aerial view of prairie potholes, Missouri, Couteau, North Dakota, USA, 2007

Shattil & Rozinski / Aerial view of prairie potholes with agricultural encroachment, North Dakota, USA, 2003

Jim Brandenburg / Prairie potholes, a unique area where shallow depressions resulting from the scouring of glaciation create important waterfowl nesting habitat, Ordway Prairie, South Dakota

Jim Brandenburg / Prairie potholes and the critical waterfowl nesting habitat they provide, damaged by freshly ploughed agricultural fields, South Dakota

Jim Brandenburg / Farmlands encroaching on prairie potholes, North Dakota

Jim Brandenburg / Farmlands encroaching on prairie potholes, South Dakota

Doug Wechsler / Prairie potholes, Missouri Coteau, North Dakota, USA

Jim Brandenburg / Sunset over prairie potholes, South Dakota