Just got back myself – rode Bootleg two days. I drove out to All Mountain Cyclery – about 30 mins from The Strip but they also do Hotel pick ups. I guided myself but they also do guiding for groups. Bike hire starts at $55 for half day (4 hours). Once there you can ride to the trails.
If you look at the trail map the right hand side is easily navigable, on the left a lot of the signs have gone missing so navving is more difficult. Check out the Vid for a taster (BTW ‘International Freerider’ is tongue in cheek !)
[video]http://vimeo.com/40258273[/video]
On balance it is good for a spin but if you are looking for thrills Vegas has lots more to offer