In recreation demand models non-participation is usually estimated as the probability mass on zero demand given a positive level of expected demand and a discrete distribution of demand outcomes. Researchers have attempted to improve predictions of non-participation by modifying the parameters of the demand distribution. This study departs from previous approaches by explicitly incorporating non-participation into the behavioral model. The choice to participate is described by a distribution of preferences combined with a choke price on individual demands to distinguish participants from nonparticipants. The model is found to accurately predict non-participation and the size of the user group.