As part of the Rio Grande Valley National Water-Quality Assessment
Program, samples were collected at 34 sites in the upper Rio Grande Basin
in Colorado and New Mexico during June and September 1994. The focus of the
sampling was on trace-element concentrations in the water column, suspended
sediment, and bed material. Water-column samples were analyzed for major
constituent, nutrient, dissolved organic carbon, and dissolved trace-
element concentrations. Suspended-sediment samples were analyzed for suspended-
sediment and total trace-element concentrations. Bed-material samples were
analyzed for nutrient and total trace-element concentrations. Physical
properties of the water column also were measured at each site.