The site of the Col-des-Roches is located in the Neuchâtel Jura at the French-Swiss frontier. It was first a rock cave, a prehistoric shelter, and was then used for many purposes : as early as the XVIth century as an underground mill, at the beginning of the electric era as an experimentation place, during a great part of the XXth century as a frontier-slaughterhouse, in the sixties as a disparate industrial site and recently as a tourist attraction. Now it has just been transformed into a museum. The ethnography of its evolution is presented in an exhibition the museography of which enables to approach the various political, economic and cultural problems at stake. Starting from the wish for a museum this ethnography shows, by means of personal and collective strategies, how an economically precarious region produces its history as a function of the present.