The River - Interview with Oren Peli

How did this come about and how much of a production challenge was it to do this outdoors?
OREN PELI: It actually started with an idea that I had for a movie, which was much more simple than the way The River has evolved. It was just going to be about a documentary crew that had gone missing in the rainforest, and filming the rescue mission to find them. I developed this idea with a couple of my producing partners, and we just put it aside and went on to produce other films. Then, I had a meeting with Steven Spielberg and he said, “Hey, we should do a TV show together.” I was thinking, “Okay, sure, whatever you say.”
At that point, I was barely figuring out the world of movies. I had no idea about anything to do with TV, and I tried to come up with some cool idea for a TV show. And, months went by and I didn’t have any idea. Then, one day, we were just hanging out with the writer of Paranormal Activity 2, chatting about ideas for movies that we thought about and never produced, and we were telling him about this idea for the missing rainforest expedition. He went crazy for that and was like, “Why waste that on one movie? You can turn it into a whole TV show and, every episode, they get into another adventure.” And then, we came up with the idea of making it on a boat on the river and pitched it to DreamWorks, and they loved it. We kept developing it, and then Michael [Green] and Zack [Estrin] came on board, and it became The River.

Source: Full interview @ Collider