Hey Aud............
Thanks for the tip on that book by Sheldon, we are online as I write looking for a copy.
Your mention of "a wasteland called Sierra del Rosario" is outstanding. It's a range so close but now so inaccessible due to the presence of the Cartels and the restrictions of the Biosphere Reserve. Once, one of my most favorite places, we used to camp out there in a south facing canyon with giant vertical granite rock slabs covered with five thousand year old injun graffiti and thousands of impact scars from 50 cal. and 20 mm. projectiles from US Army WWII aircraft. The range is unusual in that it has an east-west alignment while almost all others in the region have a north-south alignment. This means that the north face of the range is almost always shaded from the direct sun. While the south face gets burnt to a crisp. That range is loaded with Bighorn Sheep that used to be almost fearless of humans. I've had many come right up to our camp at night sniffing around our Jeep, mostly looking for water I assumed.
There is no road to get to the Sierra del Rosarios from the north, one must cross almost ten miles of small drifting dunes which makes it off limits to most larger 4x4 vehicles. The southern access would be through the gigantic dunes that you can see from the Coastal Highway. The only vehicles that can do it would be serious dune buggies as the dune heights and deep swales make it almost impossible for even a modern Jeep. There is a trail from the east, now off-limits because of the reserve that was the old infamous Camino del Diablo. The ruts made by wagons then later early autos are still evident, cuts through the flats are up to five feet deep even today. At one time there was a rest stop with gas and whatever at the mouth of the canyon that I mentioned. The cement slabs of structures are still there. Nearby are crap heaps just loaded with stuff that would make a metal detector have wet dreams.
Years back, when I had a scientific interest in that "Island in the Dunes" I constructed a bunch of trap lines, actually pitfalls, to order to see if there were any oddities there that had been isolated from the hard ground long enough to maybe differ from the outlying types. I did in fact collect quite a few animals, mostly lizards and snakes that weren't much different but now isolated from their relatives that now live many miles to the east. These included Horned Lizards, Earless Lizards, Collard Lizards and Geckos.
I finally had to give up my studies there when the narcos established an airfield south of the rest stop at El Saguaro between the highway, the Sierra del Alacranes and the trail south to the dunes and on to the range. I often wonder how many hundreds if not thousands of innocent little critters have fallen into those death traps since I last checked on them
JJ