The U.S. Geological Survey, along with scientists from Rutgers University, collected water chemistry, electromagnetic, redox-potential, dissolved oxygen, water flow rate, and water temperature data along stream and river corridors in multiple sub-watersheds of the East River Science Focus Area (SFA) near Crested Butte, CO. The concept of 'river corridor' science recognizes that the quality of flowing surface waters is intrinsically linked to their contributing catchments through hydrologic connectivity, including lower terrestrial hillslopes, floodplains, and riparian zones. Bidirectional river-floodplain exchange in particular can be critical to basin water storage and nutrient transformation dynamics, yet floodplain hydrologic exchange flows are often driven primarily by episodic high-flow events or relatively slow-exchanging, long hyporheic flowpaths. Beaver (Castor canadensis) disrupt these abiotic floodplain exchange drivers by actively diverting large quantities of channel water laterally using an engineered series of dams, impacting both wet and dry season floodplain connection. As beaver ponds and seepage zones accompanying beaver activity often exhibit suboxic to hypoxic conditions, there is the potential to mobilize reduced metals from alluvial sediments to streams and rivers. The data contained in this release can be used to assess beaver-induced physical and chemical river-floodplain exchange.