I have this posted on reddit as well but it seems like everyone’s pretty stumped so. If I had to guess the movie was probably made late 90’s early 2000’s, I watched it around 2003 on letmewatchthis.com. It didn’t have any notable actors that I can remember.
It wasn’t the entire class that went, just five or six students, and I don’t think it was punishment for failing or anything like that. I remember them in a classroom at the start, rounded room with bleacher type seating, then I want to say they spend a brief night together before the trip, which is when it shows the professors ulterior goal of using the outing as a social experiment. I can’t remember if the students read the entry that night or the morning after but they immediately go on the trip. The middle of the movie is pretty vague for me, I do remember them going missing one by one and there being evidence of foul play but I don’t believe they ever saw any “bodies”. Towards the ends, before it’s just him and the female student left, he finds the harpoon gun. I can’t remember if it had some sort of significance as to why they were in that particular area for the school trip or if it was completely random but, as I said, it did strike me as particularly odd. When it’s just him and her left he asks her what she’s done (or something along those lines) and instead of answering she smiles and reaches behind her. Assuming she’s reaching for a weapon he shoots her only to realize she was reaching for her cellphone. I’m pretty sure he drops the harpoon gun, before running out of the woods and to the closest town. It’s either a diner or a bed and breakfast, I really want to say it was a two floor B&B, but he runs in and spots his missing students sitting at a table laughing and eating. They ask what took so long, then where the female student is, while he just stares at them in horror before the movie cuts.
Only one person dies the entire movie! I’ve already crossed off after dark, after midnight, the fear, april fools day, cry wolf, silent scream, the philosophers, the geographer drank his globe away.