A Recreation Research and Demonstration System (RRDS) consisting of 24 Recreation Research and Demonstration Units (RRDU's) and 9 Recreation Use Monitoring Stations (RUMS's) has been activated by the Office, Chief of Engineers. The RRDS is a stratified 6 percent sample of Corps water resource development projects for which the Corps exercises operational control over the recreation and related natural resources (RRDU's) plus representative examples of important recreation projects for which the Corps is not now credited with responsibility. The sample accurately mirrors the size, geographic distribution, attendance, and administrative mode found in the Corps-wide system of projects. The purpose of the system is to provide permanently designated outdoor laboratories for the conduct of research in the physiographic, social, economic, and institutional aspects of recreation and related natural resources. (Author).