The Environmental Monitoring and Assessment Program (EMAP) was a national research program run by EPA’s Office of Research and Development from 1990 to 2008 to develop the tools necessary to monitor and assess the status and trends of national ecological resources. Initially, resources included estuaries and coastal waters, wadeable streams, lakes, wetlands, forests, agroecosystems, arid areas, and landscape ecology. Later, this was narrowed down to just the aquatic resources. EMAP collected field data from 1990 to 2006. EMAP's goal was to develop the scientific understanding for translating environmental monitoring data from multiple spatial and temporal scales into assessments of current ecological condition and forecasts of future risks to our natural resources. EMAP aimed to advance the science of ecological monitoring and ecological risk assessment, guide national monitoring with improved scientific understanding of ecosystem integrity and dynamics, and demonstrate multi-agency monitoring through large regional projects. EMAP developed indicators to monitor the condition of ecological resources. EMAP also investigated designs that addressed the acquisition, aggregation, and analysis of multiscale and multitier data. Monitoring of the nation’s aquatic resources is now being routinely conducted by the National Aquatic Resource Surveys, run by EPA’s Office of Water.