This report was written on the twentieth anniversary of the Outdoor Action Program to identify the unique contributions Outdoor Action has made to Princeton University. The Outdoor Action Program has been an important program for building community at Princeton for the past twenty years. Outdoor Action activities serve as powerful group bonding experiences that help students develop new friendships, learn leadership skills, increase interpersonal skills, develop concern for the environment, and learn lifelong wilderness skills. The overall success of the program can be seen through the yearly increases in participation and evaluations and studies of participants and leaders. This report documents the history and growth of the program since its founding in 1974.