On March 24, 1999, the National Marine Fisheries Service (NMFS) published its final decision to list the Upper Willamette River evolutionarily significant unit (ESU) of chinook salmon as threatened under the Endangered Species Act (ESA). The effective date for the final listing was May 24, 1999, and the ESU is defined as 'all naturally spawned populations of spring-run chinook salmon residing below impassable natural barriers' (64 FR 14308). Critical habitat for this ESU was proposed on March 9, 1998 (63 FR 11482), and this proposed designation is still pending at the time of this Biological Opinion. Upper Willamette River chinook salmon occur within the action area of this consultation. The Upper Willamette River steelhead ESU was listed as threatened under the ESA (64 FR 14517; March 25, 1999) simultaneously with Upper Willamette River chinook salmon, but its range does not include the action area for this consultation 1 , and it is not addressed in this Biological Opinion. The objective of this Biological Opinion is to address the effects of providing a license to operate the McKenzie project, as proposed by FERC, on listed UW chinook salmon and bull trout, and to determine if this federal action by FERC will jeopardize the continued existence of either species. It will also serve as a conference opinion on the effects of the proposed action on proposed UW chinook salmon critical habitat. Until FERC issues a license for the McKenzie project incorporating the reasonable and prudent measures of this Biological Opinion, the existing project has no authorization for take of listed species