The pressure on the ecosystems of the mountains of northern Sweden has increased over the last hundred years as a result of, for example, hydropower and infrastucture development, mining and tourism. This paper discusses the impacts of a highway project between Kiruna and Riksgränsen, in a sensitive mountain area in northernmost Sweden. The study has a holistic and dynamic approach including components from bio-, earth- and social sciences. The project was carried out in three stages; the first covering the construction period between 1978-1984, the second 1985-1989 and the third from 1990-1997 describing the long term impact after the opening of the road. The studies include the monitoring of the water environment, vegetation changes, air pollution, wear, outdoor recreation, economic development, land use changes etc. The main result show that environmental impact decreased rapidly after the period of road construction. On the other hand, human activities were not greatly affected during the construction phase, but after the road was opened the number of visitors to the area increased for a few years. We could also observe increased secondary effects, such as land use changes and new construction stimulated by the opening of the road.