The Rhyryn River flows gently from Tallin where it splits from Rhy Lake. It can be readily navigated both North and South and has few rapids. It is deep enough for heavy barges, but nothing of more significant profile in the water. There are a number of fish that live in the river, including the infamous Glimmerfin and many fisherman successfully ply their trade on the water.
Just south of Shearcliff, on the west side of the river, Sloughwallow Swamp stagnates. It formed from the runoff of the river into the low-lying area, but never quite formed a lake. The road along the west side of the Rhyryn up to Silk Town from Rhyryburg is a berm that now separates the swamp from the river.