Indices for objectively quantifying the severity of meteorological, agricultural, and hydrological forms of drought are discussed. Indices for each drought form are judged according to six weighted evaluation criteria: robustness, tractability, transparency, sophistication, extendability, and dimensionality. The indices considered most promising for succinctly summarizing drought severity are computed for two climate divisions in Oregon for 24 water years, 1976-99. The assessment determined that the most valuable indices for characterizing meteorological, hydrological, and agricultural droughts are rainfall deciles, total water deficit, and computed soil moisture, respectively.