note Chief is the nickname of the man that had a bad experience in the cave first. So it would be Cheif's possesive.
John "Chief" Kulka  I belive is his real name was a long time raft guide/ kayaker at the NOC.
As the story goes he got stuck in the cave swam lost gear, hiked out, got lost on hike, friends
paddled out, couldn't find him for a while.  Once they did find him he had great stories about a local
inviting him into a trailer for some beer and television.
Chief is also known for some spectacular antics as a raft guide.  He could tell jokes for hours on end
and is famous for his morning call to breakfast for raft guides.  "Wakey wakey eggs and bakey take
your hands off your snakey."
Cheif's rapid is the name.