The Foam River (often referred to as the River Foam) is a tributary of the Andoshen River of northwestern Andoran. It skirts the southern foothills of Droskar's Crag before cutting across the Darkmoon Plain between the Five Kings and Aspodell Mountains and flows in an easterly direction through Darkmoon Vale. It runs past the small town of Falcon's Hollow and punches through the Wolfrun Hills via a narrow gorge filled with rapids and shallows before joining the Andoshen. The river is less than 150 miles in length in its entirety.
The River Foam cannot serve as a highway. Not even riverboats can pass through the Wolfrun Rapids. The few ferries and boats on the river were carried overland or built on the river. No bridge spans the river, but two fords and one ferry provide ways across the Foam. One of the river’s fords lies a few miles upriver from the remains of a bridge that was destroyed in the Rending of 3980 AR and the other lies just upriver from where the Foam joins the Andoshen. The only ferry crosses the river at Falcon's Hollow.
In the spring and autumn, the river is filled with large, silver-flanked salmon, spawning at the base of Gold Falls. Crawdads, otters, fisks, marles, herons, and alligators live all along the river. Occasionally reefclaws and water nagas make their way to the river.