• View of the Monument across the Snake River

    Hagerman Fossil Beds

    National Monument Idaho

Trees and Shrubs

Rabbitbrush

Rabbitbrush

NPS

Wetland plants such as cattails and bulrush are plentiful along the Snake River. Native dry land vegetation, including big sagebrush and rabbitbrush, survives among the lava rock boulders.

Flora on the upland plateau was once a vast complex of Wyoming big sagebrush (Artemisia tridentata ver. wyomingensis) association. Some of the Monument's west boundary areas were cleared and now support common rabbitbrush (Chrysothamnus nauseosus), and introduced grasses and weeds.

Vegetation on the Monument’s bluffs is sparse in many areas due to the steepness of the slopes and low precipitation.

Greasewood (Sarcobatus vermiculatus) and rabbitbrush are the dominant shrubs where the soils are more alkaline. Scattered occurrences of four-wing saltbush (Atriplex species) occur where soils contain more calcite. Russian thistle (Salsola kali), the ubiquitous tumbleweed, predominates on disturbed sites.

Did You Know?

Hagerman Valley as it appears today.

Lake Bonneville overflowed its rim about 15,000 years ago in southeastern Idaho near the present day city of Pocatello. The Snake River cut down through the ancient flood plain sediments and deepened and widened the Hagerman valley.