This U.S. Geological Survey (USGS) Data Release provides phytoplankton data from Upper Klamath Lake, OR and Upper Klamath River, OR from 4/29 - 10/15/2019 from eight sites and zooplankton data from Upper Klamath Lake, OR from 4/16 - 10/15/2019 from three sites. Phytoplankton data are reported to the lowest possible taxonomic level and biovolume, biomass, and density are reported. Zooplankton data are reported to the lowest possible taxonomic level, animal concentration and biomass are also reported.