Seconding the underappreciated hiking and wilderness access that Vegas provides. This excellent site is a huge portal to all natural areas, trails, etc. in the area: www.birdandhike.com
It's really the redeeming feature of Las Vegas events for me. In addition to the places that are within an hour or so, you're only about 3 hours from both Zion and Death Valley National Parks and only something like 4 1/2 to the Grand Canyon.
Every time that I fly now into Vegas for business or competitions, it's a matter of routine for me to drive up to Charleston peak, and the Red Rock area - it's only an hour away. It's all too easy to snub one's nose at the strip for everything that it is... I can simply say it has almost no draw for me. I invariably rent a car and head out the desert.
I strongly second Bird and Hike! Such a great resource. I've emailed the creator (Jim) and he was super responsive; he encouraged suggestions or corrections too.