An application of a successful triad of modeling, monitoring, and research, oriented toward Chesapeake restoration, and in use since the mid-1980s will be described. Supporting the Chesapeake restoration are the integrated Chesapeake Bay models of the North American airshed, a watershed model of the Chesapeake, an estuarine water quality model of the tidal Bay, and ancillary living resource, land use change, and climate change models. Using the integrated Chesapeake Bay models allows for a full accounting of estimated nutrient and sediment loads delivered to the Chesapeake. The models track nitrogen, phosphorus, and sediment transport, and assess their ultimate fate and influence on Chesapeake water quality. The role of environmental modeling in the Chesapeake restoration in the historic Chesapeake TMDL will be described and future directions in watershed modeling requiring fine scale spatial data will be explored.