This historical data set consists of 178 permanent 1-m2 quadrats located on semi-desert grasslands at the Santa Rita Experimental Range, Arizona, USA. Individual plants in these quadrats were identified and mapped annually (in most cases) from 1915 to 1933 and again in 1947. Quadrats were located in ungrazed exclosures and in pastures grazed at various intensities by livestock. These data provide unique opportunities to test the interactive effects of grazing and climate variables on demographic rates, plant–plant interactions, and population and community dynamics. We provide the following data and data formats: (1) the digitized maps in shapefile format; (2) a tabular representation of centroid or point location (x, y coordinates), basal or canopy cover (m2) for plants mapped as polygons, perimeter length (m), and seedling and clone status for each individual plant record; (3) quadrat information including elevation, livestock grazing history, and proximity to closest long-term rainfall gauge; (4) monthly precipitation values for those gauges; (5) a species list including synonymy of names and plant growth forms; (6) an inventory of the years each quadrat was sampled; and (7) summary information on unmapped plants in each quadrat. Data files at http://esapubs.org/archive/ecol/E093/132/default.htm