We used Passive Integrated Transponder (PIT)-tagging and a series of instream PIT-tag interrogation systems (PTIS) to investigate life-histories, populations, and efficacy of habitat restoration actions for steelhead Oncorhynchus mykiss in the Wind River subbasin, WA. Our tagging focused on parr in headwater areas of the subbasin and our PTISs provide information on movement of these parr, which is primarily, but not exclusively downstream. The PTISs also provide data on life-history aspects of other steelhead life-stages. The Wind River subbasin in southwest Washington State provides habitat for a population of wild Lower Columbia River steelhead and is an excellent watershed for long-term studies of population dynamics and responses to restoration of this wild population. Much data on steelhead population metrics have been gathered from the Wind River providing information on habitat restoration actions and ongoing research into steelhead life histories. Additionally, the Wind River is an excellent control watershed of an exclusivly wild steelhead population to which basins with hatchery programs can compare. No hatchery steelhead have been planted in the Wind River subbasin since 1994, and hatchery adults are estimated to be less than one percent of adults in any year (pers comm. Thomas Buehrens, Washington Department of Fish and Wildlife). Numerous restoration actions have been implemented in the subbasin, including the removal of Hemlock Dam on Trout Creek in 2009. Data from our study, and companion work by Washington Department of Fish and Wildlife (WDFW), will contribute to Bonneville Power Administration’s (BPA) Research Monitoring and Evaluation (RM&E) Program Strategy of Fish Population Status Monitoring (www.cbfish.org/ProgramStrategy.mvc/ViewProgramStrategySummary/1), specifically the sub-strategies of: 1) Assessing the Status and Trends of Diversity of Natural Origin Fish Populations and to uncertainties research regarding differing life histories of a wild steelhead population, 2) Assessing the Status and Trend of Adult Natural Origin Fish Populations, and 3) Monitoring and Evaluating the Effectiveness of Tributary Habitat Actions Relative to Environmental, Physical, or Biological Performance Objectives. During summer 2015, we sampled and PIT-tagged age-0 and age-1 steelhead parr in headwater areas of the Wind River subbasin to characterize population traits and investigate variable life-histories, including growth and parr movement downstream prior to smolting. Throughout the year, we maintained a series of instream PTISs to monitor movement of tagged steelhead parr, smolts, and adults. Detections at the instream PTISs showed trends of parr 8 emigration during summer and fall, in addition to the expected movement of parr and smolts in spring. These data are increasing our understanding of varied life histories of juvenile steelhead; paired with other steelhead population work in the subbasin we hope to better understand the factors influencing parr movements. Monitoring of PIT-tagged fish over multiple years is providing information on contribution of various life-history strategies to smolt production and adult returns, as well as identifying factors influencing parr movement. Movements of PIT-tagged adult steelhead were also monitored with our instream PTISs. These data have provided information on timing of adult movements to various parts of the watershed, which allows us to assess adult returns to tributary watersheds within the Wind River subbasin. Determination of adult use of tributary watersheds is providing data to contribute to evaluation of the efficacy of the removal of Hemlock Dam on Trout Creek. Hemlock Dam, located at rkm 2.0 of Trout Creek was removed in summer 2009 and had contributed to hydrologic impairment of Trout Creek. Evaluating restoration efforts is of interest to many managers and agencies so that funding and time are allocated for best results. The evaluation of various life-his