From the bloggers at Rolling in a RV.
Most of the casinos in Reno do not allow overnight RV parking or have lots that are too small but overnight parking seems to be okay at the Atlantis which has a very large lot located across the street from the casino.
The farthest away spaces are used by employees. Behind them is a gravel section where trucks and RVs were parked while we were there. We parked in the middle spaces between the employee parking and the street.
To read the full story by Rolling in a RV, click here.