Some great routes through the Kofa Wildlife Refuge.  An area named after the King of Arizona Mine, these roads take you to some very remote sections.  I wouldn't recommend travelling without a satellite device for emergency use as there is no cell coverage in the east side.  Very remote.  I have camped two days out here before without seeing another person.  Staying at the Hoodoo cabin is first come first serve and is free, looked after by the BLM.  My ideal ride is to do an overnight and camp there.  The closest towns are Quartzite, AZ to the north and Yuma, AZ to the south.  I would ride to Quartzite and top off fuel before exploring if you drive from Yuma.  Caution, flash floods and road flooding are common during or just after storms, but roads in this area dry out quickly.