During the summer of 1961, the Public Health Service and Oregon State Sanitary Authority cooperated in several water quality surveys on the lower Willamette River downstream of Oregon City. Sampling station locations were midstream at No. 1 - SP and S Bridge (R.M. 7.0); No. 2 - Steel Bridge (R.M. 12.0); No. 3 - Staff Jennings (R.M. 16.5). The three stations were sampled every two hours at midstream for a 24-hour period. Measurements were made at the surface, mid-depth, and bottom 1/ of dissolved oxygen, biochemical oxygen demand, sulfite waste liquor, pH, and temperature. The BOD and SWL were sampled at mid-depth only. River stage data was made available by the U. S. Weather Bureau which operates a recording water level gage in the Portland Harbor.