Despite calls for a more collaborative approach to rural planning and policy making involving land use agencies in the British Isles, there remain few instances of formal inter-agency data exchange and integration to address applied management tasks. The well-rehearsed argument that Geographic Information Systems (GIS) present a technology whereby spatially consistent data from a variety of different sources can be integrated to address environmental problems is challenged by the lack of truly collaborative exercises of this nature. Potential reasons for this are outlined with reference to an early study - the Rural Wales Terrestrial Database (WALTER) project - in which we developed a GIS for a pilot area of Wales within a multi-agency framework. The technical and organisational problems encountered during the course of this project are addressed in relation to attempts at improving accessibility to digital data in the 10 years following the publication of the Chorley Report and in the light of recent technological developments such as the use of Internet-based GIS in collaborative planning. The WALTER project is seen as an important reminder of how a collaborative approach to data handling within a GIS environment can have proven and demonstrable benefits to the agencies concerned given appropriate organisational structures.