The main filming of the film kicked off on April 29, 1996, first at Hell's Half Acre, 45 miles outside Casper, Wyoming, and then to South Dakota. Since the locations used as extraterrestrial scenes in the film are very remote, it is a difficult problem to solve the board and lodging of 500 people in the crew. Every day, the crew must take the cast and crew who live in various places to the studio. Producer Marshall raised the difficulties faced by the crew to Natrona County officials, and the county government later agreed to build a road leading to the location. In addition, when shooting in South Dakota, the crew also built a two and a half mile road leading to the location.
In order for the actors to fully experience the role of military life, the crew organized a 10-day military training before the filming started. The actors have to run two miles a day, in addition to quality training, they also practice the use of weapons, and they eat military ready-to-eat rations.
The huge and terrifying alien insects in the film originate from Van Hoven and Tippet’s extensive research on spiders and other insects. In order to design the details of the insects, many macro photos of the insects are used, and each insect in the film is based on reality. A patchwork of different kinds of insects in the. According to the design drawings, the staff creates a three-dimensional model, which completes the computer graphics model, and helps the special effects department to complete the full-scale model.
