It drains an area of over 400 square miles ( 1,000 km ) on the western foothills of the Cascade Range and within the Oregon Coast Range .
Cow Creek is a medium - sized river in southwestern Oregon , a tributary of the South Umpqua River .
Cow Creek drains an area of over 400 square miles ( 1,000 km ) on the western foothills of the Cascade Range and within the Oregon Coast Range .
Cow Creek is a medium - sized river in southwestern Oregon , a tributary of the South Umpqua River .