This document introduces the viable salmonid population (VSP) concept, identifies VSP attributes, and provides guidance for determining the conservation status of populations and larger-scale groupings of Pacific salmonids. The concepts outlined here are intended to serve as the basis for a general approach to performing salmonid conservation assessments. As a specific application, the VSP approach is intended help in the establishment of Endangered Species Act (ESA) delisting goals. This will aid in the formulation of recovery plans and can serve as interim guidance until such plans are completed.