Metal concentrations in streambed sediment in the lower Klamath River basin, 2018-2024 (ver. 2.0, April 2025)

The U.S. Geological Survey is monitoring metal concentrations in streambed sediment pre- and post-dam removal in the lower Klamath River basin. Concentrations of aluminum, arsenic, cadmium, cobalt, chromium, copper, iron, potassium, magnesium, manganese, nickel, lead, titanium, vanadium and zinc were sampled at 10 mainstem sites, four tributaries and two reservoirs. Mainstem and tributary collections occurred once annually in 2018, 2019, 2021, 2022 and 2024. Reservoir sediment samples (Copco and Iron Gate) were collected in 2020.