In 2003 the Oregon Workgroup (Workgroup) of the Oregon Northern California Coast Technical Recovery Team (TRT) convened to review and analyze information that could shed light on historical populations of Oregon Coast coho salmon (Oncorhynchus kisutch). This document presents the preliminary conclusions of the Workgroup. A historical perspective describing how these populations functioned is an important first step in assessing the viability of present-day populations, in developing delisting criteria, and as an overall recovery strategy.