While the prairie surrounding Capulin is grazed by cattle, the prairie and grasslands within the monument are preserved in their native state. Unfortunately, interspersed among the native grasses are several nonnative plant species that disrupt the ecological integrity of the mixed-grass prairie. Common Mullein, Houndstongue, Hoary Cress, Cheatgrass and Russian Thistle are just some examples of invasive nonnative plants that are competing with the native species. The monument, through its resource management efforts, renders aid to the native prairie plants and actively discourages the invasive exotics.