In 2015-2016, physicochemical properties and chemical characteristics of stream water, bed sediment, groundwater, and soil were determined in watersheds located outside of, but in proximity to, the Peason Ridge Training Area and Main Post at the Joint Readiness Training Center and Fort Polk boundaries to document background trace element concentrations. Water samples were analyzed for physicochemical properties, major inorganic ions, selected trace elements, and dissolved organic carbon. Selected trace elements included antimony, arsenic, cadmium, copper, iron, lead, manganese, mercury, and zinc. Stream bed-sediment and soil samples were analyzed for major inorganic ions, selected trace elements, and grain size distribution. Surface-water samples were collected near the downstream transect of each stream reach. Monitoring wells were located adjacent to the stream reach and in close proximity to the surface-water sampling sites. Bulk bed-sediment samples were collected during normal low-flow conditions. Each sample consisted of a composite sample from five locations (right edge, left edge, and center of a middle transect, then upstream and downstream of the middle transect) within each stream reach. Three soil samples, one from hilltops, one from side slopes, and one from riparian zones, were collected from areas adjacent to each stream reach. Each soil sample consisted of 5 to 10 grab samples collected by a 21-inch-long, 5/8-inch internal diameter stainless-steel hand auger and composited in Teflon lined pans. All samples were collected following USGS sampling protocols. This data release provides database and mapping information for assessment of trace element concentrations in stream water, bed sediment, groundwater, and soil found in relatively pristine and undisturbed watersheds in proximity to watersheds used for military training.