Experiments have been conducted on the French full-scale experimental site at Lautaret pass to improve our understanding of the action of snow avalanches on obstacles. The ultimate objective is to provide realistic pressure distribution models suitable for use in civil engineering design and to eliminate the restrictive assumptions currently used in this field. We focus on the feasibility of using the inverse method to quantify the action of the avalanche from its effects on realistic structures rather than from sensors placed directly in the flow. This approach takes into account the interactions between the flow and the obstacle and ensures that the result is effectively the action experienced by the obstacle. The inverse analysis procedure is developed and validated using both numerical and laboratory tests. In situ tests carried out at the Lautaret site to determine the avalanche action at different scales confirm the reliability of this original approach. Its intrinsic characteristics make it especially suitable for application to different structures to provide new knowledge in this complex field.