The river arises from a catchment of just 40 square kilometres in the
Whicher Ranges. For much of its middle reaches it passes through land
cleared for agriculture, especially viticulture. There is a weir across
the river just above the town. The mouth of the river is a small
estuary, closed to the ocean by a sandbar that opens only seasonally.
Margaret River is presumed to be named after Margaret Wyche, cousin of John Garrett Bussell (founder of Busselton) in 1831
