Outdoor education researchers have accumulated a notable cache of work documenting the outcomes of participation in outdoor education programs (e.g., Hattie, Marsh, Neill, & Richards, 1997; Kaplan & Talbot, 1983). While continuing this work remains an important task, some researchers are turning their attention toward understanding the process of outdoor education. The outdoor leader is one course component that is common in all programmatic outdoor education experiences and authors agree that the relationships that form between participants and leaders are important and influence outcomes (McKenzie, 2003; Mitten, 1995; Sibthorp, Paisley, & Gookin, 2007; Walsh & Golins, 1976). Understanding how outdoor leaders can encourage healthy, constructive relationships between themselves and participants might be a vital step in understanding the process through which participants realize outcomes. One important element of positive interpersonal relationships is interpersonal trust. Trust is "the willingness of a party to be vulnerable to the actions of another party based on the expectation that the other will perform a particular action important to the trustor" (Mayer, Davis, & Schoorman, 1995, p. 712). Relationships that maintain a high degree of trust in a leader appear to influence outcomes positively. Although the outdoor education literature offers little understanding of trust development or the outcomes of trusting relationships, cross-disciplinary literature has documented many relevant outcomes such as learning, cooperation, and group performance that are influenced by trust in a leader (Dirks & Ferrin, 2002; Mayer & Gavin, 2005; Rotter, 1967). Therefore, the purpose of this study was to test a model of trust development as it occurs between participants of outdoor education programs and outdoor leaders. The model of trust presented by Mayer et al. (1995) provided the initial independent variables for developing the present model of trust development. However, a number of modifications were made to the Mayer et al. (1995) framework as it was applied to outdoor education. Mayer and his colleagues suggested three leader attributes: ability, benevolence, and integrity. Of these factors, ability was further divided into technical ability and interpersonal ability, in order to remain consistent with outdoor education literature (Priest & Gass, 2005; Sheridan, 2004; Swiderski, 1987). In addition, the definitions of benevolence and integrity were altered to reflect the orientation of the leader toward the participant and toward other group members, respectively. Further, leader gender was added as an additional predictor variable. The Mayer et al. (1995) model also proposed that each individual's unique, dispositional "propensity to trust" would influence decisions of trust. Citing mixed results regarding the effectiveness of this variable to predict trust, the present study replaced propensity to trust with dispositional optimism. A final variable, situational context, was added to test how the immediate situation might moderate the effects of technical ability, interpersonal ability, benevolence, and integrity.