It was one of the first films with the theme of city-dwellers against the powerful forces of nature. Best Picture, Best Director, and Best Film Editing. The increasingly claustrophobic, downbeat film, shot in linear sequence along forty miles of a treacherous river, has been looked upon as a philosophical allegory of man's psychological and grueling physical journey against adversity. A group of urban dwellers test their manhood and courage, totally vulnerable in the alien wild, and pit themselves against the hostile violence of nature. As they progress further and further along in uncharted territory down the rapids, the men 'rape' the untouched, virginal wilderness as they are themselves violated by the pristine wilderness and its degenerate, inbred backwoods inhabitants.
Survivalist skills come to the forefront when civilized standards of decency and logic fail.
The river is the potent personification of the complex, natural forces that propel men further and further along their paths - testing their personal values and accentuating what has been hidden or unrealized in civilized society. The adventurers vainly seek to be 'delivered' from the evil in their own hearts. The flooding of the region in preparation for a dam construction project alludes to the purification and cleansing of the sins of the world by the Great Flood. They're gonna flood a whole valley, Bobby, that's why. They're gonna stop the river up.