There is a tour company that operates a white water rafting concession in the Grand Canyon. You make a reservation, pay the fee, get in the boat, and enjoy the ride.
You can check this under :http://www.nps.gov/grca/planyourvisi...fting.htmThere you will find links for rafting operators.If you want to read a great book, concerning a trip through the Grand Canyon, you should buy this :William H. Calvin : the river that runs uphillHave a nice dayK.