Found a place in Page that has 8 acres of secure storage - rate is $45 - for 1 to 30 days to park a rig. They also have a convenience store and showers on site.
Antelope Recreation Center Boat / RV Storage
910 Coppermine Road
Page, AZ
928 645 3835
Hours are 6am - 10pm.
I called them. Reservations not necessary for open storage. Just show up and park.
I'll likely be headed up on Friday night before the run. Will camp somewhere just outside of Flagstaff that night and then drive the 2 hours to Page from there and park the Dodge. From there it's on to Alstrom Point on Lake Powell for the Night zero camp on Saturday.
So there you have it. Page is an easy stop for before and after the run and only requires about a 40 mile round trip longer on the last day to get tow rigs than it would be to drive straight home from where we dump out on the highway. Page is about 5-6 hours from Phoenix metro, depending on where you live.