It depends on which side of the Grand Canyon you want to see. It's about a 45 minute drive from to the west rim of it in Chloride, AZ, from Las Vegas, roughly the same to the north rim at Overton, NV, to as much as a 6 hour drive to the main part of it, as it is 3 hours north of Flagstaff. Helicopter or scenic flight would be the fastest way there. They have scenic flights and day trips by air from the North Las Vegas airport (VGT). It's a 40 minute flight from there. Daytrip there, horseback through the canyon if you'd like, flight back. It would be a bit expensive because GCN is a tourist trap airport, but it would be worth it.
BL.