Gail is a teacher at a school for the deaf, and shakily married to architect Tom. It's their son's birthday, and Gail is determined to take Roarke rafting down her favourite river before it is destroyed by progress.

What is supposed to be a family event turns sour when they meet up with Wade and Terry at the ranger station at the river. They just happen to have robbed the local cattle sale of its proceeds and are using the river as a getaway, which involves running The Gauntlet, a particularly treacherous set of rapids that is off limits to all.

Of course, Gail is one of the very few people to have run The Gauntlet, having been a guide on the river in her younger days. Wade connives to "coerce" Gail and the family to take Terry and him (plus $250,000) through The Gauntlet when their original guide decides to up and leave them on the river bank. What follows is a quite absorbing thrill ride down the river towards the ultimate destiny with The Gauntlet.

http://imdb.com/title/tt0110997/ (less info)