- This report assesses climate change impacts and associated community and ecosystem vulnerability. It was compiled by a group of Oregon State University researchers and students, outreach specialists, and coastal community members in Tillamook County, Oregon (OR). Through sustained engagement with the Tillamook County Coastal Futures Knowledge to Action Network (TCCF KTAN), a suite of alternative scenarios for exploring adaptation strategies for reducing vulnerability to coastal hazards based on a variety of drivers of change was developed. These alternative scenarios were explored using Envision, a spatially explicit multi-agent modeling platform supporting scenario-based planning to examine interactions between the coupled human and natural coastal system. At its foundation is the identification of key stakeholder desires and outcomes for the future of the coastal shore (e.g., access to the beach, resilient infrastructure, etc.). These self-expressed outcomes are the orienting principle of this KTAN driven process. Probabilistic simulations of extreme total water levels, long-term coastal change, and storm-induced dune erosion along the shoreline allowed the group to represent the variable impacts of SLR, wave climate, and the El Niño Southern Oscillation in a range of climate change scenarios through the end of the century. Additionally, researchers explored a range of alternative futures related to policy decisions and socioeconomic trends using input from KTAN participants. The impact of both policy scenarios and climate change scenarios on a range of participant defined metrics were quantified. In some scenarios, model results suggest severe reductions in beach accessibility (one metric highly valued by the TCCF KTAN) by the end of century, due to the cumulative placement of riprap backshore protection structures. Flooding and erosion to coastal buildings and infrastructure also increases on a variety of scales depending on the types of policies implemented. In general, human decisions introduced greater variability and uncertainty to the impacts to the landscape by coastal hazards than climate change uncertainty.