My boyfriend travels to Vegas frequently on business and when I can I try to tag along and we'll make a mini-break out of it.
I'm usually solo for a large portion of the day while he's in meetings so I'm constantly trying to find new un-Vegasy things to do because the Strip gets real old, real fast.
Red Rocks is a little bit of raw, unadulterated heaven in the most unsuspecting place. It is soooo far removed from the beat-down, drunken, degenerate, booze-fest that has become Vegas. Don't get me wrong, I do enjoy all the gaudy goodness that Vegas has to offer but sometimes you just need to mix-it-up.
The park itself is pristine and full of well preserved natural beauty. The visitor center (located just behind the entrance gate) had a ton of info. I spent almost an hour just walking around the place. Then I got back in the car to drive around the park which is just a 13 mile loop. I wasn't wearing the proper footwear so I didn't do much hiking. I just stopped at each of the trail heads, got out looked around, meandered down a few trails and took it all in. It was easily one of the best afternoons I ever spent in Vegas and I would HIGHLY recommend it to anyone visiting the area and interested in breaking up the monotony.
It's a short trip from the strip, you can make your visit as intense or uninvolved as you want but you will definitely leave with your Mojo in proper working order.