So wide is the distribution of ponderosa pine, that it becomes difficult to describe. It grows extensively throughout the western United States, as well as in British Columbia and Mexico. In general, ponderosa pine grows in semi-arid environments, characterized by limited precipitation, often falling in the form of spring snows. The occurrence of ponderosa pine alongside Douglas-fir on moist sites, and western juniper in dryer areas illustrates the tree's tolerance of variable moisture regimes. In Washington, ponderosa pine grows at elevations close to sea level, while in the southern reaches of its range, it grows as high as 10,000 feet.