The county's fire and rescue squad was dispatched to the river in reports of a kayak that went over the Maryland Falls at 6:20 p.m., a spokesperson for the department said.
One kayaker self-extricated on the Virginia side. They were treated and released by Fairfax Fire while another was removed by the Park Police helicopter in a stokes basket, and taken by helicopter to a hospital, officials said.
Their red kayak remains stuck in a hydraulic current, unable to be recovered.
Click here to follow Daily Voice Gaithersburg and receive free news updates.