Great Rivers Ecological Observation Network (GREON℠) Developed by the National Great Rivers Research and Education Center (NGRREC) in 2013, the Great Rivers Ecological Observation Network (GREON) program is establishing a network of real-time water quality monitoring platforms in the Mississippi River Watershed. The mission of the program is to advance the science and understanding of large-floodplain river ecology by collecting and sharing high temporal resolution data on key water quality parameters with scientists, managers, and the general public. Data captured by GREON is made available via NGRREC's Great Lakes to Gulf Virtual Observatory (GLTG). GREON is additionally supported by a scientific advisory committee that includes representatives from academic institutions, federal and state agencies and other partner organizations. NGRREC partnered with YSI Inc. to design and launch monitoring platforms capable of near real-time, continuous collection of water quality data. GREON researchers launched the first Pontoon for In-situ Characterization of Environmental Systems (PISCES) monitoring platforms in May 2013 on the Upper Mississippi River System. The program has expanded to deploy additional platforms both along the main stem and in subwatersheds of the Mississippi, Missouri and Illinois rivers. Each GREON monitoring unit uses state-of-the-art sensor technology mounted on a floating platform for in-stream measurement of a suite of water quality and weather-related parameters including water temperature, specific conductivity, dissolved oxygen, turbidity, chlorophyll, blue-green algae, fluorescent dissolved organic matter, nitrate and orthophosphate. Due to challenges with unit cost, maintenance and security, NGRREC is currently exploring other monitoring platforms for future consideration by the GREON science advisory committee. GREON continues to grow with the GLTG application by identifying additional ways to analyze collected data through comparisons with federal, state and local agency water quality data. With this growth, there is an opportunity to pivot some of its monitoring resources to question-based data collection. As more organizations and agencies like the USGS continue to expand investment in real-time water quality monitoring on big rivers, GREON can explore other emerging technologies, as possible directions for the network's future growth.