The Chesapeake Bay Program and the U.S. Geologic Survey are compiling tributary basin summaries for 12 major tributaries or tributary groups in the Chesapeake Bay Watershed. These summaries summarize the following information: (1) How tidal water quality changes over time; (2) How factors that drive those changes change over time; and (3) Current state of the science on connecting change in aquatic conditions to its drivers. These summaries are provided on the CAST website (https://cast.chesapeakebay.net/Home/TMDLTracking#tributaryRptsSection) and a story map has been developed for the Potomac River: https://wim.usgs.gov/geonarrative/potomactrib/. Project cover Photo by Will Parson/Chesapeake Bay Program.