Entwash

The Entwash rose in the hills of Fangorn, near the springs where Treebeard had his house at Wellinghall, and came out of the forest's southern eaves as a swift stream. Fed by the Snowbourn from Harrowdale and by the Mering Stream from Halifirien, it grew wide and slow as it crossed the grasslands of Rohan in a broad curve, and it ended in the Mouths of Entwash, a maze of reed-beds and channels where it met Anduin below the Emyn Muil. The Elvish name Onodló has the same meaning, the river of the Ents.

For the Rohirrim the river was the axis of the realm: the country east of it was the Eastemnet, rolling and less settled, and the country west of it the Westemnet, where most of the people lived. The King's herds of horses grazed along its banks, and the Riders could water an army anywhere along its length. It was fordable in many places in the summer but broad in flood.

The Éothéod settled the valley of the Entwash after T.A. 2510. In February 3019 the Uruk-hai of Saruman carried Merry and Pippin across the Eastemnet north of the river towards Fangorn, and Éomer hunted them down at the forest's edge. Treebeard drank from the river's springs and told the hobbits its name. Later that year, as the Ents diverted the waters of the Isen against Isengard, the Entwash ran on undisturbed. After the War of the Ring Rohan's herds returned to the plains along its banks in peace.

The Entwash ran roughly from north-west to south-east across the whole of Rohan, from Fangorn to the Anduin, a distance of well over two hundred miles. Its mouths formed a great marsh opposite the southern end of the Emyn Muil and above Cair Andros.