I have seen both Black/ Grey, and a separate fresh honey Wagon out there as well and have a card rom the guy last year. He used to hang out on CB Ch. 8 under the handle of "turdman".. Just call and tell him where you are.
After that there is the Pit Stop on 95.. Full service dump, refill, fresh, and LP. Gets REALLY busy during show week but they bang em' out pretty quickly
Ps- here is the number I have for one of the services direct. Remember that all these folks roll in for the show/ winter, so if you call now just make sure you ask if they will be in Quartzsite this coming year... They may or may not be.
(928) 446-3660
Firewood has been for sale across the street from Gambler RV the past few years