Years ago I used this in the NW PHX area:
Coyote Pass RV & Mini Storage -
www.coyotepassrvstorage.com9355 N El Mirage Rd, El Mirage - (623) 935-1480
I have been past this one, which is fairly new at the west end of the valley:
White Tanks Storage
16835 W. Northern Avenue,
Litchfield Park, AZ 85340
White Tanks Storage is located on the southwest comer of Loop 303 and Northern Avenue, with easy
access to 1-10, Loop 101 and Highway 60.