 Typically the highlands range from in height.The mountains and plateaus, which consist of limestones, sandstone, quartzite, schists and dolomite, have been created by faulting and folding processes.The crest of the range is defined by the watershed or boundary between the drainage basins of rivers which drain directly eastward into the Pacific Ocean, or southward into Bass Strait, and those rivers which drain into the Murray–Darling river system towards the west and south.