ABSTRACT
Agriculture has the longest history of any economic activity in Colorado. The state's present farmers had predecessors perhaps as far back as 0 A.D., and Indians, Spaniards, and Anglos have all had farmers among their members. At one time, the majority of Colorado's people were farmers or ranchers. Although their numbers are quite small, and on the decline, farmers and ranchers still make a large contribution to the state's yearly income. Terrain is an obvious constraint on agricultural land use. Steep slopes, rocky and thin soils, and high erosion susceptibility all go together to exclude cropping. In Colorado, such conditions occur most often in the mountains, and much of this area has a growing season that is too short for any crops. Climate is a very important element of crop farming in Colorado and, to a lesser extent, of livestock raising. In this context, aridity is the most important aspect of Colorado's climate.
