Five hundred and twenty different kinds of plants were documented in Fossil Butte National Monument by fall 2003.

In 1984, Dr. Robert Dorn and his coworkers mapped and categorized the monument's vegetation into fourteen types: Aquatic (rooted in water), Aspen, Barren, Alkali Sagebrush (low sage); Basin Big Sagebrush, Mountain Shrub, Saline, Wet Meadow, and Willow. Their distribution is controlled primarily by the depth, clay, and moisture content of the soil, but some types, like the Barren type, which occurs on ridgetops, are controlled by the force of the wind.