Many environmental factors, both natural and human-caused, have produced dramatic changes over time both in the biotic and abiotic communities of the memorial. Natural factors such as geologic and hydrologic activity, weather and climate, and historic fire regimes have profoundly shaped the geology, flora, and fauna seen today in the monument. More recent human-caused factors, such as recreational development, fire suppression, grazing, mining, and inadvertent or deliberate introduction of non-native species, have increased the rate of environmental change.