Casino security does patrol this lot several times a day, yet they never knocked on our door or otherwise spoke to us. When we arrived there, we found several RVs that still remained there after we left, suggesting you’re welcome to park for as long as you want. The best we could determine, the casino has no official maximum length of stay, and no official policies beyond the normal parking policies that apply to their other lots. Sash and I set up our toy hauler here in March of 2018 for 4 nights. The Casino maintains a policy of allowing visitors to park their RVs in a special lot located behind the old bowling alley.
Morongo Casino, located in Cabazon, CA, is just minutes away from Palm Springs, and thus is a popular place for some free RV boondocking.