 As the mountains of the Cascade Range were too far from Vancouver to serve as a location, the film crew settled on a nearby forest that had a partial view of the mountains.The set used for the exterior of the field base camp was later sold to the production company responsible for the TV series "The Sentinel", while the interior was shot inside a British Columbia hydro sub station.A set was built to represent the interior of the volcano, and footage filmed there was achieved through the use of a crane.