The largest dam removal project in U.S. history is set to begin in 2020 on the Klamath River in Siskiyou County, according to documents filed recently with federal regulators. The Klamath River Renewal Corp. plans to begin site work in two years to remove four dams on the Klamath River and deconstructing the dams will begin in 2021, according to the “Definite Plan for the Lower Klamath Project.”