Large roads and railways may block the movements for ungulates, and work in concert with other anthropogenic barriers and disturbances in the landscape, such as power lines, pipelines, wind farms, waterways, hydro-power dams, industry, tourism facilities and other built-up areas. Restrictions of the free movements are particularly problematic in areas where animals conduct seasonal migrations, as is the case for ungulates in northern Scandinavia. Reindeer in this region are semi-domestic, herded and tended by indigenous Sami communities in a traditional transhumance system, but with deer free-ranging all year, largely following their natural and pre-historical migration routes and seasonal ranges, and subsisting on natural feed. For the reindeer, as for wild migratory ungulates, fenced roads and railways may effectively stop animals from following their preferred routes or reaching crucial seasonal areas and resources, thereby reducing individual condition, fitness, reproduction, and winter survival. For the reindeer husbandry, roads and railways with fences or high traffic volumes tend to create severe obstacles during droving of large herds, require extra efforts to retrieve stray animals, and result in loss of odd individual animals to unknown fates. On that, deer are frequently hit or killed by traffic on unfenced sections of roads and railways, causing further loss. In effect, the cumulative impacts of roads, railways and other human developments threaten both the reindeer population and the traditional lifestyle and livelihood of these indigenous communities. We present a current example of cumulative impacts on reindeer of multiple exploitation around Kiruna in north Sweden. The mining industry in the area has brought about a rapid development of roads and railways, urban and industrial areas, and tourism including leisure snowmobiling and off-road hiking. Traditional migration routes for reindeer through the area has been cut off, and new, alternative routes are deemed inferior because they entail increased risks for the animals or difficulties for the herders. In response, reindeer herders try finding ways to avoid this migration bottleneck, by, for example, transporting part of the herds by truck to the winter range, or keeping the deer on supplementary feed over winter near the summer ranges. While many individual reindeer in the area still conduct the long-distant (ca. 100 miles) annual migration between upland meadows in summer and lowland boreal forests in winter, this natural system has started eroding. Reindeer herders and traditional Sami knowledge provide an extraordinary insight in the ecology and behavior of reindeer in all arctic Scandinavia. Despite some functional differences between semi-domestic and wild species, we believe that the study of reindeer can be a door to a better understanding of cumulative impacts also on wild ungulates and other wildlife, of which our knowledge otherwise tend to be limited and scattered.