Looks like you have some company.
After a town hall meeting on health-care reform in Belgrade, Montana, President Obama will escape to Big Sky country on Friday evening where he'll spend time with family and go fly-fishing for the first time.
The Gallatin is nice, but if you staying in Big Sky, don't miss out on fishing the Madison. Check with Blue Ribbon flies, a great shop in West Yellowstone, about where/how to fish.
http://www.blueribbonflies.com/
I would definitely send Flybop a PM for some info too. He is a first-class guide out there and will surely take care of you if you booked him.
You'll love it out there.......have a ball.