Answer: watershed

AnswerCrossword Clue
WATERSHEDGreat divide
WATERSHEDTransition point
WATERSHEDTurning point
WATERSHEDMajor transition point
WATERSHEDRain-catching area.
WATERSHEDThe Great Divide is one.
WATERSHEDRiver basin
WATERSHEDEvent marking a turning point
watershedthe area which a river and its tributaries drain
watershedAn area or region drained by a river, river system, or other body of water
watershedAn event or period marking a turning point in a course of action or state of affairs
watershedAn area or ridge of land that separates waters flowing to different rivers, basins, or seas