The country beyond, where this long range falls off, continues an extensive open stony plateau or plain, occasionally intersected with watercourses, the course of the line of road being west of north.

Most of these watercourses on the plains fall into Lake Eyre, another and more northerly salt depression.

A curious limestone formation now occurs, and for some hundreds of miles the whole country is open and studded with what are called mound-springs.

These are usually about fifty feet high, and ornamented on the summit with clumps of tall reeds or bulrushes.

These mounds are natural artesian wells, through which the water, forced up from below, gushes out over the tops to the level ground, where it forms little water-channels at which sheep and cattle can water.