Some of the bigger outfits may expect more than say the smaller rancher types but I would say 10% or so.
Most guides really appreciate anything you give them, they do not expect every hunter to be able to afford a huge tip.
Get to know your guide, work with him or her and relay any issue you may have about your ability in the mountains and do what they tell you while hunting.
You'll be able to determine what they were worth. If they're lazing and do really nothing to get you on an elk, tip should reflect that.
Don't forget the cook, a tip would be most appreciated if food is good. Even $100 is appreciated.
