Fun Things to do outdoors.?

My husband is currently deployed but will be home in about a mth. We've done really well this last year but he has 30days leave once he's home and I wanna come up with something to do just the 2 of us but we don't have any museams or anything around here, we're going to Vegas for a week. Is there anything that doesn't cost a bunch but that we can do outdoors?