In a survey of Canadian university students (N = 205), the relationship between majoring in an outdoor recreation university program and environmental concern, cooperation, and behavior were examined. Stepwise linear regression indicated that enrollment in outdoor recreation was predictive of environmental behavior and ecological cooperation; and these results held independently of age and gender. We then examined the possibility that environmental concern may mediate these relationships. Inclusion of ecocentrism as a mediating variable indicated that environmental concern partially accounted for the relation between outdoor recreation and self-reported environmental behavior, and fully mediated (reduced to nonsignificance) the relationship between outdoor recreation and ecological cooperation. Results are discussed in the context of education, and more specifically experiential outdoor education as promoting environmental behavior through greater concern for the ecosystem. (Contains 2 figures and 4 tables.)