About search dogs and heat: Reduced olfactory efficiency in sniffer dogs results mainly from overheating, and causes physiological and behavioural resources to be diverted from concentration on the assigned task and applied instead to methods of body cooling. Dogs do not possess sweat glands, and panting is the main means of cooling the body. Since a dog can either sniff or pant, but can never perform both actions simultaneously, panting causes a decrease in sniffing rate. (https://www.sciencedirect.com/science/article/abs/pii/S0168159102002745) Just putting it up again in brief, as the subject keeps coming up. Scent works on molecules that are partly water. Scent is dispersed by wind. Dogs that have to pick up a scent on site (on the trail in this case) will be confused if more than one person has been there. Dogs need a good item to sniff from (RT and all of Barb's things in the trailer were gone by Monday). Even under ideal conditions, dogs are only about 70% accurate. Many people have been lost in the desert, the area searched, and they are found later. Human searchers working in the heat are not as reliable (it got up to 114-115 in the afternoons around Day 6 of searching, it was 104-105 on the other days). There are a variety of plant habitats that you can see in the search pictures (where they searched repeatedly). But nothing in the many SAR photos tells me that (for example) they searched 2 miles down and 1 mile off Hidden Hills in each direction (4 square miles - a big search area for a grid search). I'm sure they did search it (using reasoning) but they did not search it as much as they searched the western side of Kelbaker, clearly. Search was called off eventually as the heat increased. The temps listed above were in the shade and the search was obviously not in the shade. Put a bunch of us in a room that's 115-120F and start giving us tests or tasks and you'll see that we mostly perform more poorly than we would if it were, say, 75F. Searchers are used to higher temps, of course, but there's a limit to how well the human brain does in situations like that. SAR personnel suffer heat exhaustion too (have a colleague with severe consequences to a heat experience, right now - unfolded in the second week of August). Someone asked where Barbara would go or where she would get lost, and why. Just consider that she could have been disturbed, upset, overheated, angry, scared and she might also have felt threatened by something. She could have taken off intending to get to the RV, found herself unable to find the key, walked off into the desert to relieve herself (irritated), walked further than intended (for privacy), etc. MANY scenarios. As someone who takes long walks when upset/angry and have many times found myself someplace without a clear idea of why I was in that particular place...I do think it's possible she is out there, beyond the original search perimeter, or within that perimeter but under foliage as she sought shade. People will eventually curl up under almost anything if they don't just pass out. I do believe that the man in Joshua Tree, who is still missing, will be found eventually due to the high volume of people who go there. Mojave NP is a bit different and that's what concerns me. That's why the word needs to get out to regular users of Mojave and Mojave Trails NP's. (I add in Mojave Trails just in case).