Historic accounts and recent observations of Pacific lampreys (Lampetra tridentata) at mainstem Columbia River dams indicate the number of Pacific lampreys migrating upriver has decreased dramatically over the last 60 years. Consequently, state, federal, and tribal governments have recently expressed concern for this species. Little is known about the biological and ecological characteristics of habitats suitable for upstream migrating Pacific lampreys. If rehabilitation efforts are to be done effectively and efficiently, we must gain knowledge of factors limiting survival and reproduction of Pacific lampreys. From data gathered in the first year of this project, we can for the first time, describe the timing, extent, and patterns of movements for Pacific lampreys. We have tested methods and gained information that will allow us to refine our objectives and approach in future work. Knowledge of behavior, timing, and the resulting quantification of habitat use will provide a means to assess the suitability of overwintering and spawning habitats and allow the establishment of goals for recovery projects. Further research is necessary, including multiple years of data collection, tracking of movement patterns through the spawning season, and more rigorously examining habitat use.