Heck yeah, lots of good stuff out there! Here's a quick snap shot of my favorite places to ride and I'd recommend all four of them: Bear's Best, Cotton Wood starting from Blue Diamond, Cowboy Trails, & Bootleg Canyon.
As John mentioned above, Las Vegas Cyclery can dial you in on the latest trail insight (my friend Jared owns it & he has good peeps that are in the know) as well as Mike from Eye Gear Sports Optics (same shopping center), who's one of the best riders I know & a good friend.
Here's a few links you've probably scene.
Bear's Best has some of the best views of Vegas and awesome trails!
https://www.strava.com/activities/1456649408
https://www.strava.com/activities/1448739502
Cotton Wood from Blue Diamond, NV is vast and one of the original places mtb playgrounds... nothing but smile miles out there below the Red Rock Bluffs.
https://www.strava.com/activities/1451876398
https://www.strava.com/activities/102349495
Cowboy Trails - More technical orientated trail system but it's one of my favorites.
https://www.strava.com/activities/102117670
Bootleg Canyon is fantastic and covers everything from cliff hucking to smooth and flowy... a must do!
https://www.mtbproject.com/directory/8011519/bootleg-canyon
I'll send ya some more links once my bandwidth opens up.