Analyses of water- and sediment-yield records from the Walnut Gulch Experimental Watershed, the San Simon Wash Basin, and the Jornada Experimental Range, combined with observations of regional variations in climate, geology and soils, vegetation, topography, fire frequency, and land-use history, allow estimates of present conditions of water and sediment discharges in the upper Animas Creek Basin, New Mexico. Further, the records are used to anticipate fluxes of water and sediment should watershed conditions change. Results, intended principally for hydrologists, geomorphologists, and resource managers, suggest that discharges of water and sediment in the upper Animas Creek Basin approximate those of historic, undisturbed conditions, and that erosion rates may be generally lower than those of comparison watersheds. If conversion of grassland to shrubland occurs, sediment yields, due to accelerated upland gully erosion, may increase by 1 to 3 orders of magnitude. However, much of the released sediment would likely be deposited along Animas Creek, never leaving the upper Animas Creek Basin.