The Picacho Peak state campground on the west side of the Colorado river, due north of Yuma Arizona (in the California desert). This is NOT the Picacho Peak AZ park!!!
In the Desert, Picacho Peak, California, Picacho Gold Mine, Maps.google Map.
This is my home turf, and the desert there is stunning. But you want to make sure you are not there between May and Sept as the heat can be scorching in the summer. I was just there this past Christmas, when I took my son home to explore where I grew up. Needless to say, he loved it.
At the end of the Picacho road there is a campground on the river where you can base for a day or two exploring the desert around the park. AFAIK there are NO facilities, no electricity / sewer, not even water, although the river is right there. Lends a whole new meaning to "boon docking"!
Expect to see desert tortoise, burros (gone wild from the old miner days), deer, rattlesnakes and roadrunners, tarantulas and scorpions. I even saw a badger once. Barrel cactus, ocotillo, and creosote bush, mesquite trees and ironwood are native to the area - ironwood is so dense that it won't float. To see the wildlife, walk at sunrise and sunset as that is when the desert springs to life.