Europeans founded Santa Fe in 1610. It is likely that use of the Caja del Rio for the grazing of domesticated livestock began shortly thereafter. From the beginning of colonization until the 19th century, subsistence users treated the plateau as common property, and used it for summer grazing and timber harvesting. During the mid-19th century, commercial livestock ranching increased throughout New Mexico. By the 1890s, grazing levels throughout the Territory were as high as 9 million animal units. This overuse, combined with severe droughts in 1891 and 1892, led to the loss of top soils and major vegetative changes. Among the vegetative changes were the replacement of more palatable forbs and grasses by woody shrubs and trees.