The source of the river is in southeast Brown County, near Richard J.

[3] On its course it passes through the unincorporated communities of Kingsbridge and Shoto.

About 6 miles (10 km) upstream from its mouth, the West Twin River is blocked by Shoto Dam, which divides the river into upper and lower reaches.

[4] The river below Shoto Dam is broad, shallow, and slow and the water quality is poor, while above the dam it is narrow, deep, and fast-flowing with good to excellent water quality.

[5] Major tributaries of the West Twin River include:[6]