Humans continue to influence the park environment. Though technology has advanced, it has not lessened the human impact. The scenic vistas continue to change through development, both inside and outside the park. Air pollution from urban areas and seasonal fires, both prescribed and wild, further impact the air quality and scenic vistas. Through time, humans have introduced nonnative plants and animals, which continue to disturb the native species. While hiking the trails or visiting the cliff dwellings, noise pollution from planes flying over the monument or vehicles on the roads below may be present.
Weather shapes the desert and its occupants. Plants change with the seasons -- budding, blooming, bearing fruit, and losing leaves. Animals bear and raise their young. Both plants and animals adapt as the cycles of heat and drought come and go. With more violent storms, changes occur rapidly within the desert. Water races down arroyos, further carving the water channels. Carrying soil and rocks into larger washes, the water combines with rainwater from other hillsides and canyons. Gathering speed, these flash floods erode stream banks, widen and cut new washes, forever altering the landscape.