The James drops approximately 5 inches (130 mm) per 1 mile (1.6 km), and this low gradient sometimes leads to reverse flow.
[2] The river arises in Wells County, North Dakota, approximately 10 mi (16 km) northwest of Fessenden.
It enters northeastern South Dakota in Brown County, where it is impounded to form two reservoirs northeast of Aberdeen.
Flowing southward across eastern South Dakota, it passes Huron and Mitchell, where it is joined by the Firesteel Creek.
This name was subsequently anglicized to James River,[3][4][5] which was the name used by local English speakers at the time Dakota Territory was incorporated.