There are many. In fact every January (last half of the month) there is a 2 week long RV Rally in Quartzite, AZ (not sure of spelling)
If you take State Route 95, about oh, 5 to six miles SOUTH of I-10, on the right is a Free BLM parking area with easily two or three HUNDRED hams parked on it.
They call it "QuartzFest".. Gordon West is usually there. Many others.. I've been there. Tons of fun,, Swap, Seminars, Presentations and more. Great place to visit.
YOu can also look for the open roads radio net (sorry no url handy)
I'm listening to a Kenwood TS-2000 as I type this.