Technical Abstract: Perennial grasslands that dominated the southwestern US during the past 10,000 years have been desertified to varying extents. Desertification is a temporal phenomenon, defined as a change in the scale of the spatial distribution of resources. We report here on several indicators of desertification using bare patch indices as surrogates for direct measures of desertification. A bare patch index based on canopy cover, which is relevant for precipitation and wind driven erosion, is not equivalent to another bare patch index based on soil surface measurements, which indicates overland water flow driven erosion. Percent grass cover, percent long-lived grass cover, percent cover of vegetative reproducers and a relative preference index all yielded sensitive indicators of desertification. The usefulness of some indicators, such as organic litter, is dependent upon recent environmental history. Other indicators, such as percent cover due to species resistant to grazing, appear not to b sensitive to desertification and need further development. Range site type may also be important in determining indicator responses, where some indicators were sensitive to range site while others were not. Overall, we have identified several sensitive indicators of desertification based on vegetational characteristics in varied range sites in the northern Chihuahuan Desert.