Since its development by Jim Bradley in the late 1970s, the Impact Monster, a wilderness education skit designed to teach minimum impact techniques, has been used as a wilderness education tool by federal land management agencies. This paper reports on an evaluation of the perceived effectiveness of the Impact Monster program and its content. Results indicate that the Impact Monster program remains a widely used wilderness education tool to teach appropriate wilderness behavior. In addition, the program is rated good to excellent by most study participants. Most participants considered a figure clothed in bright colors an effective program element. Fourth, fifth, third, and sixth grade children, respectively, were considered the most appropriate recipients of the Impact Monster program. Problems experienced with the program included children fearing the gun used in the skit, wilderness educators tired of presenting the program, and sixth to eighth grades and high school students identifying too strongly with the Impact Monster. The most frequent suggestions to improve the program were: avoid stereotypes, be sensitive to cultural differences, acquistion of props, emphasize positive behavior, maintain program flexibility, and develop evaluation methods. Behavioral objectives established for the program should focus on Leave No Trace principles, which establish a land ethic that promotes appropriate behavior, recognizes impacts, and increases wilderness knowledge.