Potatisbacken is one of five moraine formations around the village, and it owes its shape to a hole in a dying ice sheet. Meltwater washed sediment down into a sink in the inland ice; when the ice finally went, the fill stood up as a cone. The result rises about 38 metres, topping out at 439 metres above sea level, and its south face does two useful things at once. It catches whatever sun this latitude offers, and it lets cold air run off downhill instead of settling in the rows. Frost that would flatten a crop on the flat delta below slides past the slope. Nils Johansson, born in 1797 and dead in 1881, is remembered as the first to plant it; he was the Grundfors man who took over the Övre Gautsträsk homestead here in 1827.

The hill is not one farm but many. Its cultivated face is split into plots, and 23 properties in the village hold potato ground on it in proportion to their land registration, with a stone at the foot of the slope marking where the boundaries begin. That arrangement is the reason the terraces look the way they do from below: not a single tidy field but a patchwork of strips, each one somebody's business, all of them planted with mandelpotatis, the almond potato that Swedish cooks prize and that has no right to ripen this far north. Nobody grows it here for the money. The hill is worked because it has always been worked, and because a village that can put its own potatoes on the table above the cultivation limit is making a point about where it lives.

Long before there were potatoes there were reindeer. The Ammarnäs area served as pasture for the Sami communities of Ran and Gran for centuries, and its population was entirely Sami until 1803, when the Övre Gautsträsk homestead was first registered; the claim then sat unused until 1820. The village carries Sami names still, Gävttse or Gávtjávrrie in Ume Sami, Geavtse or Geavtsjaevrie in South Sami, and prehistoric hunting remains ring the settlement. A chapel went up in 1858, replacing the one at Jillesnåle as the summer church site for reindeer-herding Sami, and a kyrkstad of simple wooden cabins grew around it. In the 1930s two North Sami families arrived from Karesuando, part of the state-ordered displacements that moved Sami households hundreds of kilometres south, away from land and relatives they had not chosen to leave. Reindeer husbandry remains a working livelihood in Ammarnäs today, alongside small-scale tourism.

Ammarnäs sits on the ground where the Vindelälven meets the Tjulån, its largest tributary, the two joining at Gautsträsket. In the 1960s engineers drew up a chain of hydroelectric stations for the Vindelälven; the opposition that followed was local, regional and national, and in 1970 the Swedish government decided the river would be left to run. The Riksdag confirmed that in 1993, naming it a national river alongside the Torneälven, Kalixälven and Piteälven. What survives is 445 kilometres of undammed water from the mountains to the Ume River, one of the last big free-flowing rivers in Europe, and since 2019 the spine of the UNESCO Vindelälven-Juhttátahkka Biosphere Reserve. The reserve straddles the Arctic Circle and covers more than 1.3 million hectares.

The village is a gateway into Vindelfjällen, established on 25 February 1974 and, at 562,772 hectares, the largest nature reserve in Sweden and one of the largest protected areas in Europe. Kungsleden, the King's Trail, runs straight through Ammarnäs; the stretch to Hemavan is 78 kilometres of forest, wetland, high plateau and alpine peak, usually walked in six days with a mountain cabin at the end of each. A naturum visitor centre explains what you are looking at. Getting here means driving to the end of county road 363, or a bus from Sorsele once or twice a day, or a helicopter over from Hemavan. Char and grayling fill the water, birdwatchers come for the wetlands, and the potatoes go in as soon as the ground allows.