When the directors chose Wildwood Park for the shooting location, they were originally told that they could do whatever they needed to do there to make the film. But that all changed on the first day of shooting when the park ranger stepped in and told them about all of the endangered plants and animals at the park that they could not disturb. Because of this, they were heavily restricted on where they could film.
Originally, the special forces team was going to consist of male and female members, but the studio didn't think it made sense, so it was changed to all-female.