The character "Travis" was a combination of 2 characters. Originally there was "Nick" and "Travis" but after the person playing "Travis" dropped out of the film, the movie had to be rewritten mid filming combining his parts with other characters, mainly "Nick" and Nick Walter's character had to be changed to "Travis" in order to save other scenes already filmed where "Travis" was mentioned.
The movie had to be rewritten and changed were made early in filming to change the location. Originally, the script had the main characters camping in the woods. However, due to cast availability and outdoor weather changes, the script was rewritten to take place in a cabin so that most of the scenes could be filmed indoors at different times without having to worry about changing weather and rain.