Speak with the fish and game of the state your interested in and get the harvest statistics for the unit or units you intend to hunt in.Speak with a biologist of the game you are intending to hunt and ask him or her the overall condition of the herd is it improving or declining and what area's they think hold the greatest concentrations of game,also ask for harvest statistics for present year and a couple years back to see it in black and white.
Speak with the state outfitters and guides association to see if this outfitter has any violations on file against them.Personally if I were to book a hunt I would be using a service such as Garth Carter's Huntin Fool,and even if using a service I would still do all the follow up research.An elk hunt is not cheap it pays to do all the home work you can!