The present paper aims to discuss an example of a participatory methodology, i.e. a methodology involving local people, in the construction of an extension tool. Such a tool aims at providing support to local people in order to improve access to, and manage natural resources and, thus, to achieve a more sustainable use of the natural resource base on which their production (livestock) system depends. The proposed methodology is based on the application of satellite and Geographic Information Systems (GIS) technologies in order to produce a tool enabling collective negotiations and decision-making. The innovative aspect of the methodology is that despite the high tech used it allows, on the one hand, for the direct participation of the local producers and agencies in the construction of the tool and, on the other, for planning the management of their pasturelands, flocks and production.