Understanding the water quality of U.S. streams and rivers requires consistent data collection and analysis over decades. The U.S. Geological Survey’s National Water Quality Network (NWQN) was established to facilitate national-scale understanding of surface-water quality conditions through the collection of comparable data in large rivers and small streams in different geographic and land-use settings. Data collected by the NWQN support the needs of Federal, State and local stakeholders tasked with managing our Nation’s water resources. This talk will provide an overview of the history of national-scale, surface-water quality monitoring in the USGS, current network objectives and scope, data collection and reporting methods, sampling resources as well as published products utilizing NWQN data.