Rocky Mountain National Park encompasses three different elevational ecosystems, the Montane, the Subalpine, and the Alpine. Variation in vegetation communities relates not only to elevation, but also to direction and amount of slope, drainage, moisture availability, exposure to wind, amount and type of soil, fire history, and other factors.The "boundaries" between ecosystems usually involve overlapping species and gradual transition rather than clear-cut points, but each ecosystem has some plants and animals, which are most frequently found within its limits.