Add a few extra hours to your itinerary and hit up Grapevine Canyon down near Laughlin. One of the highest concentrations of petroglyphs in the US. Easy to get to, just know the last couple of miles are offroad, but it's maintained.

You can hike up the canyon a bit, but most of the petroglyphs are right at the canyon entrance which is a quarter mile hike from the parking area. Go during the week and likely nobody else will be there.

Plus US95 goes is pretty impressive if you like wide open desert landscapes. I used to have a plant in Kingman, AZ and nearest airport was LV, I would occasionally take it back to Vegas from there for a change of scenery.

I DO NOT recommend going into Laughlin, unless you like blue hairs and bad food.