WDFW will use this grant to perform an assessment that will evaluate the abundance of juvenile spring Chinook salmon and summer steelhead in the fall, their survival through four segments of the Tucannon River and to Lower Monumental Dam, and their seasonal distribution within CHaMP sites and treatment/control strata, as well winter habitat utilization via mobile PIT tag detection building upon two previous projects (15-1322 &16-2095). This suite of information will provide critical information to direct restoration actions at limiting life stages with appropriate habitat actions. The proposed project would yield life-stage-specific survival rates for wild-origin juvenile spring Chinook salmon and summer steelhead in the Tucannon River, which in turn will help direct habitat restoration efforts based on survival and distribution of PIT tagged fish. In addition to the overwintering survival that past projects have investigated, we would also quantify egg-to-parr survival which may identify deficiencies in incubation, high flow, or summer survival.  This project will attempt to identify if, when, and where the population bottlenecks exist for spring Chinook and summer steelhead in the Tucannon River.  It builds on the four instream PIT detection sites, existing smolt trap, and habitat information available through the CHaMP sites in order to provide an improved method for identifying limiting factors and prioritizing restoration actions than are currently im