The Okanagan River is a Transboundary River with linkages to Chapters 1 and 3 of the Pacific Salmon Treaty (PST). The Okanagan River begins in British Columbia and flows southward for more than 300 km to enter the Columbia River near Brewster, Washington. Two runs of Chinook have historically returned to the Okanagan River: a spring run which returns in low numbers, and a summer run which is the focus of this report. Okanagan Summer Chinook are part of the Upper-Columbia Summer Chinook stock group that is represented in the PSC Chinook Model and has escapement and exploitation rate data reported by the PSC Chinook Technical Committee (CTC) annually. Upper-Columbia Summer Chinook return and spawn in five Columbia River tributaries and return to the Wells and Chief Joseph hatcheries located on the mainstem of the Columbia River. Since 2002, catches of Okanagan Chinook ranged from 2,800 to 10,700, with similar average catches in AABM (3,800) and ISBM (3,700) fisheries based on Coded-Wire Tag (CWT) and escapement data (escapement range: 3,400-13,900).

During the development of the 2019 PST Agreement, concerns for the conservation and rebuilding of Okanagan Summer-run Chinook that spawned in Canada were discussed and there was interest in using the Okanagan Summer Chinook for an escapement indicator stock in Appendix I of the PST. Several questions arose during the discussions, and the Commission established a work group to explore issues including the establishment of management objectives, enhancement and possible use of the Okanagan Chinook as an indicator stock.