Mount Rushmore - Ecology

Ecology

The flora and fauna of Mount Rushmore are similar to those of the rest of the Black Hills region of South Dakota. Birds including the turkey vulture, bald eagle, hawk, and meadowlark fly around Mount Rushmore, occasionally making nesting spots in the ledges of the mountain. Smaller birds, including songbirds, nuthatches, and woodpeckers, inhabit the surrounding pine forests. Terrestrial mammals include the mouse, chipmunk, squirrel, skunk, porcupine, raccoon, beaver, badger, coyote, bighorn sheep, and bobcat. In addition, several species of frogs and snakes inhabit the region. The Grizzly Bear brook and Starling Basin brook, the two streams in the memorial, support fish such as the longnose dace and the brook trout. Mountain goats are not indigenous to the area but can also be found here. They are descended from goats which were a gift from Canada to Custer State Park in 1924 but later escaped.

At lower elevations, coniferous trees, mainly the Ponderosa pine, surround most of the monument, providing shade from the sun. Other trees include the bur oak, the Black Hills spruce, and the cottonwood. Nine species of shrubs grow near Mount Rushmore. There is also a wide variety of wildflowers, including especially the snapdragon, sunflower, and violet. Towards higher elevations, plant life becomes sparser. However, only approximately five percent of the plant species found in the Black Hills are indigenous to the region.

The area receives about 18 inches (460 mm) of precipitation on average per year, enough to support abundant animal and plant life. Trees and other plants help to control surface runoff. Dikes, seeps, and springs help to dam up water that is flowing downhill, providing watering spots for animals. In addition, stones like sandstone and limestone help to hold groundwater, creating aquifers.

Through the study of tree rings, it has been determined that forest fires have occurred in the Ponderosa forests surrounding Mount Rushmore around every 27 years based on evidence of fire scars found within tree core samples. Large conflagrations are not common. Most events have been ground fires that serve to clear forest debris.