The stream rises in the Umpqua National Forest at the confluence of South Fork Cow Creek and East Fork Cow Creek.

The south fork, which is much larger, is sometimes considered the main stem.

In its first few miles the creek flows west through an agricultural valley and through Galesville Reservoir.

It then continues northwards, bending steadily eastwards and doubling back on its former course.

The river emerges from the mountains near Riddle, and bends sharply south around a ridge, joining the South Umpqua about 2 miles (3 km) west of Canyonville.