Photo courtesy of Greg
Forcey. |
Though individual prairie potholes are small, they
often occur in groups across the landscape. Potholes
are formed by glacial action and are thus limited to
areas where glaciers were present. Pothole
depressions are filled with snowmelt and rain in the
spring. Individual potholes may dry out during parts
of the year and others are essentially permanent.
The prairie potholes region in North America is one
of the most important freshwater marsh systems in
the world. |
