I will be in Vegas for a seminar soon and hope to get in a ride or two, but have no idea where to go. A few things - I can't deal with shear drops/cliffs, don't think I'll have a car - so a place that offers shuttle service would be good, and I might only have time to go once the seminar ends (after 5pm) so it needs to be close enough to get there and get in a decent ride before dark. Any recommendations?