More than 15,000 mountain rescue requests are recorded each year on the French territory. Despite the technological advances of positioning systems and the growing number of geo-applications, the location of the victims during the alert phase remains crucial to the rescue public services teams. Data heterogeneity, victim’s mountain poor knowledge and the imprecision of the travelled itinerary described by the victims are some factors that make this step difficult. The project CHOUCAS is an interdisciplinary project involving researchers from different domains such as data and knowledge management, retrieval information, spatial data reasoning, and spatial data visualization. The aim of the project, in response to the needs expressed by the Peloton de Gendarmerie de Haute-Montagne de Grenoble, is to propose: methods and tools to build and enhance spatial data coming from heterogeneous sources, fuzzy spatial reasoning models and methods, and geo-visualization tools to improve the decision making process regarding victims’ localisation in mountain areas.