The Uzboi-Landon-Morava (ULM) outflow system is a long series of channels and depressions that may have carried water across a major part of Mars.
[1][2][3] Some of the water may have helped to carve Ares Vallis.
[4][5][6][7][8] Altogether, the total area drained for this watershed may have been about 11 X 106 km2 or about 9% of Mars.
[9][10] Pictures below show the Argyre basin which was once full of water.
Also, the wider view shows the distance the water traveled, which was south of Argyre basin to Margaritifer Terra.