Rangers of the North
Gwathló (S. “Shadowy River”, from “Gwathir”); Greyflood; Ad. “Agathurush”
The greatest river of Cardolan is formed by the confluence of the Mitheithel and the Glanduin. The Gwathló flows into the Belegaer near the Númenórean ruins at Lond Daer. The current of the Gwathló is slow yet treacherous, due to shifting mud deposits and marshy banks. Each year after the snows melt, the Gwathló floods and occasionally forces the residents of Tharbad and Sudúri to seek higher ground. Despite these hazards to navigation, there is a great deal of river traffic on the Gwathló, for the sea route to Gondor remains comparatively cheap and profitable. Great ships are too cumbersome for the waters of the Gwathló, and shallow-draft barges are the most common traffic on the river.
Gwathló was named in the Second Age, when it was overhung by deep forests on both sides, shaded by tall trees. These forests were later felled, so that at the end of the Third Age, this once overshadowed river actually runs through an all-but treeless plain.