Adventure therapy (AT) and the use of activities and outdoor experiences for educational and therapeutic purposes have a long and rich history. In recent years, the popularity and use of adventure programs in schools, clinical treatment facilities, and various other settings has increased. This increased use of AT in a therapeutic context has brought it to the awareness of clinicians, consumers, and researchers. Although participation is growing rapidly, research on the effectiveness and impact has been slow to substantiate claims. This study sought to contribute to the gap that exists in the [current] research by examining the role of challenge within AT/AP experiences. The overall purpose was to investigate the relationship between challenge and subjective well-being. Specifically, the goal was to determine whether the level or degree of challenge impacts mood and whether an optimal level of challenge yields significantly more positive subjective well-being. The researcher also examined whether differences existed based on actual or perceived challenge as well as whether there was a correlation between self-report and observer-rated levels of challenge.