WATERSHED HUMAN‐USE LEVEL AND WATER QUALITY

quality of water flowing from protected watersheds was scant, the Washington State Department of Health, in the spring of 1965, requested the USPHS to study this question. Three watersheds in the northwestern part of the United States were chosen for this study. These watersheds were conveniently located near the Northwest Water Hygiene Laboratory at Purdy, Washington, had sufficient access roads to facilitate the on-site study activities, and had differences in level of human use. The Cedar River watershed was well protected, the Green River watershed was open for limited recreational use, and the Clackamas River watershed was completely open for access and recreation.