Water-quality data (July 1986 through September 1987) and statistical summaries (March 1985 through September 1987) for the Clark Fork and selected tributaries from Deer Lodge to Missoula, Montana

Water quality sampling was conducted at seven sites on the Clark Fork and selected tributaries from Deer Lodge to Missoula, Montana, from July 1986 through September 1987. This report presents tabulations and statistical summaries of the water quality data. The data presented in this report supplement previous data collected from March 1985 through June 1986 for six of the seven sites. Included in this report are tabulations of instantaneous values of streamflow, onsite water quality, hardness, and concentrations of trace elements and suspended sediment for periodic samples. Also included are tables and hydrographs of daily mean values for streamflow, suspended-sediment concentration, and suspended-sediment discharge at three mainstream stations and one tributary. Statistical summaries are presented for periodic water quality data collected from March 1986 through September 1987. Selected data are illustrated by graphs showing median concentrations to suspended-sediment concentrations, and median concentrations of trace elements in suspended sediment. (USGS)