The swamps in turn may drain westward into the Bahr el Jebel section of the White Nile or eastward into the Veveno River.
Colonel P. Molloy visited the swamp in the dry season between 23 and 25 February 1950, possibly the first European to reach the area.
Molloy's observations of wildlife tended to confirm that the water, which he found drinkable, remained year round.
When Molloy visited, the Khor Son was between 150 and 200 yards wide, winding across a flat plain between a series of shallow depressions.
He observed large numbers of pelicans, open-billed storks, wood ibis, sacred ibis, marabout, saddleback and hammerheaded storks, fishing eagles, lily-trotters, grey herons, spurwing geese, comb duck, whistling teal and common teal.