Conflict in recreation is a major problem for recreation managers who are trying to provide satisfying experiences for all recreationists. This thesis is about conflict between mountain-bikers and trampers. Mountain-biking has grown in popularity in New Zealand over the last ten years, and these increasing numbers have threatened the quality of walkers' and runners' recreational experiences, particularly in peri-urban areas. Conflict is a complex social interaction process which occurs around times of change. It involves the interplay of perceptions and attitudes, behaviour, and an incompatible situation. This complexity required the use of a range of methods to successfully understand the conflict between walkers and mountain-bikers. Like many other recreational conflicts, the conflict between bikers and trampers is asymmetrical - walkers dislike meeting bikers much more than bikers dislike meeting walkers. A majority of walker respondents disliked or strongly disliked meeting bikers on walking tracks. Walkers' questionnaire answers indicated that their greatest concerns with mountain-biking are (in order of decreasing importance) track damage and other environmental damage, personal safety, and the feeling that bikes interrupt their peace and quiet. Further exploration during in-depth interviews show that the perception of these problems are closely related to the way different users feel about that places that they use, and the way meetings with other users can be incorporated into the experiences of the recreationist. For walkers, meeting bikers is far more intrusive than vice-versa. Political activity aimed at eliminating bikers from many front country areas means that bikers are now developing a dislike of trampers who they see as intolerant and arrogant. Therefore, behaviour affects the escalation of conflict. In addition, wider social change has had an influence on this conflict. Changing economic wellbeing, less regular work hours, a perceived lack of time and a wider choice of activities have all impacted on recreation patterns in peri-urban areas, and on this conflict situation. In addition, this study has indicated that the concepts of specialisation and substitution may need modification. The use of qualitative methods has highlighted the narrow focus that researchers have used when studying these concepts. Both must be seen more broadly in the context of individuals' changing recreational needs both over the life cycle, and in the face of social change as outlined above.