The Arikaree River (ARIK) is core aquatic field site within NEON's Central Plains Domain 10. NEON's ARIK field site is located in the Fox Ranch, a 14,070-acre ranch owned by the Nature Conservancy, in northeastern Colorado, southwest of Wray, between the towns of Joes and Idalia. ARIK was once a major waterway flowing through the plains of northeastern Colorado. Large water withdrawals for agriculture have now reduced it to a stream, with highly variable flow rates across the growing season. The Arikaree is also impacted by agricultural runoff and cattle grazing. The Nature Conservancy conducts extensive research at the site on invasive weed management, sustainable grazing practices and native landscape management. Cattle graze freely on surrounding pastureland and also have free access to the stream here, providing an opportunity to investigate their impact on the aquatic ecosystem. Remote sensing surveys of this site collect lidar, spectrometer and high resolution RGB camera data. This site has one meteorological station located in the riparian area and one meteorological station above water on a buoy. The met stations are outfitted with the a subset of the same sensors used at terrestrial sites. Measurements include wind speed and direction, air temperature, barometric pressure, relative humidity, shortwave radiation, and PAR. This site has one buoy-mounted sensor station and an inlet station and outlet station. At the buoy, the automated instrument measurements are: PAR at water surface, PAR below water surface, temperature at a specific depth in surface water, water quality (specific conductivity, chlorophyll a, dissolved oxygen content, pH turbidity, and fDOM), and nitrate. At the inlet and outlet stations, the measurements are: PAR below water surface, elevation of surface water, and temperature in surface water. Eight groundwater wells throughout the site collect specific conductivity, water tempertaure, and elevation of groundwater. Field ecologists collect the following types of observational data at this site: aquatic organisms (Aquatic Microbes (surface water), macroinvertebrates microalgae, plants and macroalgae, zooplankton. Biogeochemical data on plants,sediment water and particulates.As well as physical aquatic data on bathymetric maps, stage,secchi depth and depth profiles, and riparian assessment. Total data products planned for this site: 79