The Virtual Columbia River is a skill-assessed 4D (space-time) simulation environment that offers multiple representations of circulation processes, variability and change across river-to-shelf scales. Circulation includes water levels, salinity, temperature, and velocities. Products include: daily forecasts, decade-scale retrospective simulation databases, climatological atlas, and on-demand particle tracking. This is tool is hosted by the Center for Coastal Margin Observation and Prediction (CMOP) hosted at Oregon Health and Science University in partnership with Oregon State University and University of Washington.