<p>New Zealand stands out in the global conservation scene and in the nature-based tourism industry with one third of its land area comprising the Conservation Estate (the conjunct of all public protected areas). New Zealand's Department of Conservation (DoC) is responsible for the conservation and management of the Estate, including the concession system that regulates all commercial activities on the Conservation Estate. Typically, DoC does not provide guiding services, with guided activities in the Conservation Estate almost entirely provided by tour operators that hold guiding concessions. Environmental interpretation is one of the main roles of tour guides, and DoC expects guiding concessionaires to deliver quality interpretation in order to provide quality visitor experiences; to educate tourists about natural and cultural values; to minimize the impacts of tourists; and to promote conservation advocacy. However, knowledge relating to tour operators' interpretation management and to guiding concession management is limited. This thesis seeks to understand how the concession system deals with aspects of interpretation, by investigating DoC managers' and tour operators' perceptions about the benefits and importance of interpretation; their actions and challenges to develop and monitor the interpretation capabilities of tour operators; and their perceptions on the concession system and their relationship. A mixed method approach was employed in order to gain an understanding of the situation at the national level (through an email survey), as well as at a regional level in the Nelson-Marlborough Conservancy (mostly through interviews and some observations). The national survey and the case study provided breadth and depth to the investigation. This research found that DoC managers and tour operators regarded interpretation as important or very important, but both perceived it as less important to the other party. For most tour operators interpretation was a major part of their guiding services, whereas for most DoC managers it was a minor part of their concessions related work. Some DoC managers argued that the Department should put more emphasis and resources into interpretation support to tour operators, since they are providing an important service that has been transferred from the government to the private sector. Most tour operators and DoC managers demonstrated good understanding about interpretation, particularly about its purposes and benefits. However, few participants demonstrated understanding about the principles of, and techniques for effective interpretation. This research also found that tour operators and DoC managers were undertaking a wide range of actions, and facing many challenges and constraints to develop, support, and monitor the interpretation capabilities of the operators. Some of the key implications for interpretation management of guiding concessionaires arising from this thesis are: the need for DoC to hold annual meetings with tour operators in order to support their interpretation practices, and to review regulations and minimum impact behaviour in protected areas; the need for DOC and the tourism industry to discuss the insertion of conditions and standards related to tour guide's qualification in concessions contracts; and the need to promote DoC's Interpretation Handbook and Standards.</p>