Multiple destination trips are generally involved in many outdoor recreation trips. However, existing studies employing travel cost method used to omit the issue from their study samples. Both the first-stage and the second-stage demand curve used to be estimated without considering multiple destination trips, hence resulting in the two demand curves misspecified. Authors examined the influences of multiple destination trips on traditional TCM. Authors confirmed that the number of destinations visited rises as the travel distance increases since multiple destination trips tend to be more price inelastic than single destination trips. Authors confirmed that the traditional TCM overestimates the demand of long-distance trips.