I've driven this road from the top down, starting in Joshua Tree NP on Geology Tour Road. It's a beautiful canyon. Have you gone around the GTR to the southwest corner and hiked into that canyon. It's a good place to see big horn sheep, old mining ruins and a view of the Salton Sea if you go to the top of Pushwala Plateau.
Yes I have it is quite amazing ..I actually live below that look out point and have big horn sheep just a 10 min walk /hike out my front door of mission lakes country club, still find desert tortoises and white iguanas as well which we came across one on this trip sitting on rock right next to the driver side door. But I haven't explored any of the old mining ruins.
Thinking of heading out to some trails in Mecca and painted hills this weekend.
I haven't been out through Mecca in many years. 40 years ago I used to drive up into those sandy canyons in my old 1959 VW bug. Took the back seat out and filled it with camping gear. I hope to go hike the Lost Palm oasis out of Cottonwood in a few weeks. I did a big lop hike through there last November to Black Eagle Mountain. There's a good 4 wheel road that starts near Cottonwood and ends near the 10 fwy. Off of GTR the mining ruins in that canyon are just about 20 minutes walk or so. Old rock walls and floors stand next to a steel water trough. A bit farther is a natural spring in a rock slot. You have to look for it but farther up are more old rock houses and a grist mill wheel. Going up an old truck trail to the top of Pushwala Plateau find deep shafts, small ruins and sheep and cougar tracks. Have fun in Mecca.