Those are mine, too, although I have also added Mountain Lion. The reason I added Mountain Lion is that there is an uptick in the Mountain Lion population. I had pooh-poohed the idea initially, due to water issues, but did some research and found that there is a source of water south of where the Thomases stopped. Mountain lions have a walking pace of 10 mph and attack at speeds of up to 60 mph. The rabbit population in the desert is up, due to all that extra foliage, and there were plenty of rabbits in that area, IMO.
It would be odd, though, for a lion to drag prey miles before stashing it. SAR searched such nearby stash places (and I think the sniffer dogs were there). However, if lion was feeding offspring at a distance, could have gone outside search area.
Still really improbable, but within the realm of possibility. Mountain lion fatalities in California occur every 10 years or so, but they do occur. Also, many older people have been victims, nation-wide, and a variable is the size of the victim. I think Barb looks as if she weighed around 120 lbs, not 130 as stated on her DL. I base this on the one fairly recent family photo. At any rate, 130 pounds is within a mountain lion's capacity to take. Lions often hide in sandstone outcroppings, similar to the one shown being searched in the twitter photos.
Since the more extensive search of the sandstone didn't take place until at least the next day, Lion would have cover of darkness to sneak off. HOWEVER, if they had a cadaver dog out there (surely they would have?) So...both "lost in the desert" and "mountain lion" are not such great theories.
But, a mountain lion would have put Barbara further out of the search radius than if she were on her own power, IMO. If LE/SAR suspected this, they knew that the total area to be searched was beyond the technical capacities of humans at that time of year...or any time of year, most likely.
So those are my RT-friendly theories.
The only way we'll know, if Barb was lost, discarded by a hit and run driver on some remote road, or taken by a mountain lion is when some future desert lover/ATV rider comes across skeletal evidence.
The lack of car debris near the place where Barb crossed is troubling, for the hit-n-run theory.
The "lost in the desert" is, statistically, most probable. I believe RT headed down to the creek bed (in an early report, reporter says "husband walked to a lake to take pictures" (there's obviously no lake - but there is a lake bed-like thing 14 miles north and then, there's the creek bed, which does look a bit like a dry lake and has very different rocks than the rest of the area - more like Mono Lake, which people drive a hundred miles or more out of their way to see...)
So, it's not like RT was just randomly photographing rocks. He never mentions a tripod and he does mention a gallon of water in his pack. Most rock photographers don't use a tripod for a simple shot of rock formations, as rocks don't move. The length of time he says he was there indicates it was probably his hand held camera (presumably, it could have been his phone).
Granite Mountains in the distance - with much less foliage than during the time the Thomases visited:
Granite Mountains (California) - Wikipedia
I'll try and post pictures of the white rock formations later.
The mention of the "dry lake" led many to believe they were at the Kelso Dunes area, but the 911 call says Kelbaker/HH and that's where the search took place.