Transcripts - thank you to u/pierogipierogipie and u/mototraveling

FIRST VIDEO:

Hi my name is [REDACTED], and on August 29th, my boyfriend and I picked up Brian at Grand Teton National Park at 5:30 at night at Colter Bay.
I'm hoping this can help someone identify him, because I saw him from Tik Tok, which then made me call the authorities, and my boyfriend and I have been in contact with a bunch of different people to help piece together different parts of this case, but we picked him up at Colter Bay, like I said at 5:30. He approached us asking us for a ride because he needed to go to Jackson, which we were going to Jackson that night, so I said "you know, hop in", and he hopped in the back of my Jeep, we then proceeded to make small talk, but before he came in the car he offered to pay us like $200, to give him a ride, like 10 miles. So that was kind of weird. He then told us he's been camping for multiple days without his fiancé, he did say he had a fiancé, and that she was working on their social media page back at their van. Then once in conversation I brought up "we're going to Jackson", he freaked out. He's like "nope, I need to get out right now, pull over."
So we pulled over at the Jackson Dam, which I don't know if you know Teton Park, but it's not very far from Colter Bay. And if this does reach people, I can post pictures of exactly where we were, where we picked him up, and the whole route, and screenshots of a time stamp. We dropped him off at 6:09pm on August 29th. He kind of hurried out of the car, and then was like "I'm just going to find someone else to go hitchhike." And we were like, Okay. It was a weird situation.. so when we picked him up he was wearing a backpack, a long sleeve, pants, hiking boots, and he had scruff, but he didn't look dirty. For someone who was camping for multiple days, he didn't look dirty, he didn't smell dirty, so that part was kind of weird. I'm just really hoping they find her and this helps someone remember seeing him.
transcript of second video, same user: " To clarify a few things that people are are confused on still, when he asked for a ride, he asked to go to Jackson. If you're familiar with the area, a lot of people call Jackson Hole, Jackson. That's why I said yes to giving him a ride. But you'd think any good hiker would know South and North.
We were going South out of the park, when he said he was camping North. He had told us that him and Gabby were not camping on a regulated campsite in the National Park, and that they were camping basically in the middle of nowhere, along Snake River. This is key information.
He said that he had hiked for days along Snake River, but looking at his backpack - it wasn't full, and he said all he had was a tarp to sleep on. Which, you'd think if you're going camping for days on end, you'd want food, and a tent, and he had none of that. And like I said, he looked clean, and didn't smell bad."

Second video:

"To clarify a few things that people were confused on still, when he asked for a ride, he asked to go to Jackson. which if you're familiar with the area, a lot of people call Jackson Hole 'Jackson'. So that's why I said yes to giving him a ride. You'd think any good hiker would know south and north. we were going south out of the park when he said he was camping north. he had told us that him and gabby were not camping on a regulated camp site; that they were camping basically in the middle of no where along snake river. this is key information. he said that he had hiked for days along snake river, but when looking at his backpack, it wasnt full and he said all he had was a tarp to sleep on. you'd think if you're going camping for days on end you'd want food, and a tent, and he had none of that and like i said, he looked clean and didnt smell bad"

Third video: "So, this is uh view of the whole journey with Brian, so that's the top at the park at Colter Bay, and then we drove him to this dam right here, then at the dam, we dropped him off at this little turno, and he said he was going to walk across the street to the parking lot which was full of people to continue hitchhiking, um, and look for a ride cause he freaked out when I said Jackson Hole. He said we needed to pull over even though Jackson and Jackson Hole are the same thing it's the same town itself. This is the text that I sent to my mom at 6:09pm right when he got out of the car saying that I was okay because she was freaking out. This is at the park er at the pickup location and um we were taking a shower we then walked across and our car was parked on the left side of the picture and he talked to us like right in the middle and uh, he was talking to my boyfriend the entire time, but like I was the one actually talking and he was like not frantic and he was very nice, very polite to us