Goyder's Line is a line that runs roughly east–west across South Australia and, in effect, joins places with an average annual rainfall of 10 inches (250 mm). North of Goyder's Line, annual rainfall is usually too low to support cropping, with the land being suitable only for grazing. Related to that, the line also marks a distinct change in vegetation. To the south, it is composed mainly of mallee scrub, whilst saltbush predominates to the north of the line.