Was the first WS person to visit the site
@sroad?
Yes.
I think @sroads was right at the junction where the one wider trail intersects with the main trail (that post that keeps ATV's off the trail should have been right around the "corner" where RT last saw Barbara). We don't know for sure where they parted. Early on, I swear a reporter tweeted that he said he went to a "dry lake bed" (which bolstered my view that it was the Kelso Dune area, but after learning that's not where the search was, it seems it's probably the dry creek bed?)
I do wonder if Barbara, after going to the turn-out, couldn't find the key, headed back over the road - and *then* made the wrong turn - toward the creek bed, perhaps passing over it thinking she'd meet up with RT? I can see in the videos of dogs searching on Day 2 and 3 (MOO), that the handlers are calling them back when they head north toward the dry creek because, presumably, they'd be scenting RT not BT at that point. Maybe.
We have no idea which of those trails they were on or whether they stayed on the main trail until it sort of peters out at the foot of Granite Peak/Mountains/Hills. I do not think they were equipped to climb up the Granite Hills, and the search pictures mostly show the main sandstone boulder formation, so that must be where RT said they were. Those boulders appear to have another trail that goes around behind them.
I think they must have parted near that main "intersection" with the other trail (one end goes to the dry creek). But did she follow him part way down there? Did he wander further than he said or thought he would? Was it really only a minute before he packed up and went after her? (I'm skeptical; I have a husband who says "two seconds" and that means "five minutes"; 5 minutes means 15-20; but we don't separate on hikes).
She could have gone to the lot, found herself locked out, felt very overheated, and walked back across the road thinking she could remember how to find RT, but chose one of the other spur paths. It's a possibility that makes more sense to me than abduction.