While the Bison Gear packs don't have a specific pocket for a bladder, a bladder quite nicely nestles at the bottom of the pack. I use a 3 litre Platypus with the tube running over my right shoulder and it's never leaked or caused an issue. The only problem I've had is with the mouth piece getting snagged on the string while stumping and flying off into the brush, which is actually a problem with me not tucking it away and not a problem with the product. During early season I can easily consume all 3 litres so I carry a 1 litre soda bottle and Aqua Mira water treatment for treating and refilling on the go. If you want to carry both water and a sports drink, use 2 smaller bladders.
The Badlands have a good reputation as well, I'm sure you'll enjoy it. Good luck in Colorado, it should be a great trip no matter what pack you have on your back!