Deliverance (1972)

Intent on seeing the Cahulawassee River before it's dammed and turned into a lake, outdoor fanatic Lewis Medlock takes his friends on a canoeing trip they'll never forget into the dangerous American back-country. Atlanta businessmen Lewis, Ed, Bobby, and Drew decide to canoe down the fictional Cahulawassee River in the remote Georgia wilderness, expecting to have fun and see the glory of nature before the river valley is flooded over by the upcoming construction of a dam and lake. The four encounter hostile locals, and during a pit stop, Ed and Bobby are brutally attacked by hillbillies. Lewis intervenes and kills one of the attackers, while the other escapes. The group decides to bury the dead body and keep the incident a secret. As they continue their journey, they face dangerous rapids, and Drew mysteriously disappears. Ed, Bobby, and Lewis reach a town and report the incident to the authorities, but suspicion lingers. Despite their efforts to keep the truth hidden, the men are haunted by their traumatic experiences.