see i'm having a lot of trouble with the timeline too..
for example: ok, he kills her on the 27th, then hikes 20 miles up snake river to dispose of evidence until hes picked up on the 29th at 6pm.. but this just sounds weird because she actually *wasnt* killed in a super remote part.. it's not like she was found miles and miles away. she was actually extremely close to many people. even people who were camping on the same side of the creek and closer to her than her van which was only 900ft away. so her body was there for 2 days , leaving the van and her body to be found ? the van was parked illegally and people remember seeing it because it was strange looking. so even if he left her body inside the van, hes extremely lucky no one called rangers out to ask them to move. it's honestly just really bad luck her body hadn't been found sooner.
what if he kills her when he got back from his 20 mile multi-day hike ? he gets back, gets pissed that maybe she didn't get much done on her blog or whatever she was working on... maybe the time away from him she decided she needed to break up with him and says that when he gets back... (but lets be honest, i don't think he'd let her out of his sight) kills her on sunday evening, when there would be less people around since its a sunday and people maybe had to work on monday. but if thats the case, someone would've had to have seen her the whole weekend. i can't imagine she'd just stay holed up in the van the whole time, she would've had to go outside to go to the bathroom, stretch her legs, etc...
its all so odd.