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METHODS The following key species are included in this report: steelhead (Oncorhynchus mykiss), chinook salmon (O. tslaawytscha), coho salmon (D. kisutch), sockeye salmon (O. nerka), pink salmon (O. gorbuscha), chum salmon (O. keta), cutthroat trout (O. clarki) and Atlantic salmon (Salmo salary. Of the above species, we emphasized review of work on steelhead and chinook salmon. These two species were identified as priority species for supplementation research work in the proposed Five-Year Work Plan (Supplementation Technical Work- Group, 1988). We reviewed current supplementation efforts and unpublished literature by making contact with fishery biologists throughout the study area. Agency projects and annual reports were reviewed where available. Data were recorded on a standardized form and then entered into a computerized database. Appendix A contains specific information on the individual supplementation projects we reviewed. Although we attempted to contact all the key workers involved with supplementation in the study area, we .undoubtedly overlooked some individuals. In addition to project reports, research and management biologists were interviewed to determine their opinions on how to have successful supplementation. STUDY AREA We emphasized the Pacific Northwest in our review of the unpublished literature and ongoing supplementation work. We included work being done in Oregon, Washington, Idaho, California, Alaska, and British Columbia. Some limited information is also included from the Eastern U.S. on Atlantic salmon. GENERAL OVERVIEW Anadromous salmonids have been artificially propagated in the Pacific Northwest for over 100 years. Fishery managers have used hatchery production to maintain fisheries and to rebuild runs. The question for the Columbia River Basin is "How can hatchery production be used to rebuild depleted natural runs of salmon and steelhead in this large altered river system and maintain the genetic integrity of the various stocks and races of fish?" During the past 20-30 years, salmon and steelhead hatchery propagation in the Columbia River has dramatically increased. Raymond (1988) estimated that beginning in 1970 new hatcheries were then doubling the number of smolts in the Snake River. While, in the mid-Columbia River, this doubling number was attained by 1975. Thus, after 1975 the majority of salmon and steelhead entering the Columbia River, from the Snake and Mid- Columbia, are of hatchery origin. For the Snake River Basin 80 to 90 percent of 2