From introduction: This study is limited to four U.S. Geological Survey stream-flow stations located in Idaho (figure 1). The 6 to 22 years of stations were assembled and evaluated through use of computer techniques for data plotting and regression analysis developed by Steele (1972). Objectives of this evaluation were were (1) to show which parameters were highly correlative with the levels of specific conductance and(or) discharge and (2) to see if any changes in overall chemical character of the stream had occurred over the long term.