Complex sentence: The headwaters of the river rise in the Drysdale River National Park at the foot of Tadarida Scarp then flow in an easterly direction until discharging into the Forrest River of which it is a tributary.
Split into simpler sentences: The headwaters of the river rise in the Drysdale River National Park at the foot of Tadarida Scarp. The river flows easterly until discharging into the Forrest River of which it is a tributary.