Until late in the nineteenth century, magnificent ponderosa pine forests blanketed much of the inland West. They covered perhaps 30 million acres, an area the size of New York state, spreading across the mountains of New Mexico, Arizona, and California and flourishing throughout the eastern Cascades, the intermountain Pacific Northwest, and the Rocky Mountains northward as far as British Columbia. This magazine article discusses the ecology of the ponderosa pine forests of the west, their significance to the Native Americans who used the trees for shelter, building material, firewood, and food, and the importance of fire to maintain these historically open forests.