• View of the Monument across the Snake River

    Hagerman Fossil Beds

    National Monument Idaho

Mollusks

Idaho Springsnail

Enlarged view of the Idaho Springsnail

photo courtesy of FWS

The Hagerman area has five species of freshwater snails that are listed as threatened or endangered under the Endangered Species Act: the Snake River Physa (Physa natricaria), the Lanx (Lanx sp.)the Bliss Rapids snail (Taylorconcha serpenticola), the Utah valvata (Valvata utahensis), and the Idaho springsnail (Pyrgulopsis idahoensis).

The decline of the aquatic mollusk species has been primarily attributed to changes in the river from free-flowing, cold water to impounded, slower, warmer habitats. Another variable is the population increase of non-native invasive aquatic species such as the New Zealand mudsnail (Potamopyrus antipodarum).

Did You Know?

A portion of the view from the Snake River Overlook.

The Snake River Overlook, a wheelchair accessible viewing platform, allows a view of bluffs about 600 feet high. They consist of strata, or layers of sediments (sands, silts, and clays) deposited by the flooding of rivers flowing into ancient Lake Idaho more than three million years ago.