A majority of the film was shot in 1985, but to capitalize on a narration of the story, the scenes involving Sean Astin narrating the film were shot in 1987.
The film is dedicated to its director of photography, John Alcott, who previously worked on several Stanley Kubrick projects.
The working title of this film was called "Rites of Summer".
Originally slated to begin filming in July of 1985 with a 50-day shoot, production didn't begin until mid September which caused the production to go into December. Hence, why many scenes were filmed in New Zealand. The production was also plagued with numerous reshoots which was the cause of the delay in release.
When the boys first leave Vic behind, they stop for the night with no tents and curl up because they're cold. Although Alan is carrying a perfectly good sleeping bag, he uses it as a pillow instead of using it to keep warm.