Hi everyone, I'll be in Las Vegas for a week starting next Saturday. This will be my fourth time visiting, with my pool team for APA pool league campionships, and can't wait to come back! I'm bring my girlfriend this year and she is a geology major here in Illinois. This brings me to my question. I would like to take her on one of the Grand Canyon tours, but don't know if I should book the excursion online ahead of time as suggested by the company's offering the trips, or wait till I get there and hopfully find a cheaper last minute deal? Any advise would be greatly appreciated! Thank you all.