Water-quality, bed-sediment, and biological data (October 1994 through September 1995) and statistical summaries of data for streams in the upper Clark Fork basin, Montana

Water, bed sediment, and biota were sampled in streams from Butte to below Missoula as part of a program to characterize aquatic resources in the upper Clark Fork basin of western Montana. Sampling stations were located on the Clark Fork and major tributaries. Water-quality data were obtained periodically at 16 stations during October 1994 through September 1995 (water year 1995). Data for twelve bed-sediment and eleven biological stations were obtained in August 1995. The primary constituents analyzed were trace elements associated with mine tailings from historical mining and smelting activities. Water-quality data include concentrations of major ions, trace element, and suspended sediment in stream samples collected periodically during water year 1995. Daily values of streamflow, suspended- sediment concentrations in the fine-grained and bulk fractions. Biological data include trace- element concentrations in whole-body tissue of aquatic benthic insects. Quality-assurance data are reported for analytical results of water, bed sediment, and biota. Statistical summaries of water-quality, bed-sediment, and biological data are provided for the period of record at each station since 1985.