The Variable Infiltration Capacity (VIC) model is being implemented 1/16^th degree to examine climate change impacts to 2050 in headwater systems that inflow into Williston Reservoir. Model implementation includes model forcings and vegetation, soils, and topographic data development. Gridded forcings data (precipitation, temperature and wind speed) were developed at 1/16^th degree resolution for the Peace River basin for 1950 – 2006. The gridded data was based on a comprehensive set of Environment Canada, BC Ministry of Forests Fire and Weather, Automated Snow Pillow and BC Hydro’s DCP stations, temporally corrected to remove inhomogenities using the Adjusted Canadian Historical Climate Data set, and adjusted for elevation effects using the PRISM climatology (1961 – 1990). Vegetation and soils data were built using the EOSD 1-km data set and the FAO digital soils maps and derived soil properties, respectively. The CGIAR-CSI 3-arcsecond (~90m) NASA Shuttle Radar Topographic Mission (SRTM) was used to define topography. VIC model scenarios for 2050 are projected using downscaled GCM projections that are based on the 1950 – 2006 forcings. Auto-calibration of the model is achieved by application of a multi-objective tool, MOCOM. Model uncertainty is an important consideration when interpreting and presenting results from the analysis of climate change; including model limitations, sensitivity analysis and uncertainty due to GCM projections and downscaling methods. Specifically, the northern position of this research site will be discussed in terms of uncertainty of results.