Muddus/Muttos is an unbroken assemblage of virtually primeval forests and peatlands on moraine-covered granite. It is situated just inside the Arctic circle in the area of Gällivare in Swedish Lapland. Lake Muttosjávrre lies in flat ground gorges in the southern part of the park; the Muttosjåhkå has a
waterfall with a 42-metre drop.

Granite forms the main part of the bedrock. The gorges to the south are one of the most remarkable sights of the National Park. It is likely that these came about in the Ice Age, perhaps during the catastrophic drainage during the final stage of that epoch. Other characteristic features of this landscape
are the drumlins or low ridges of glacial drift, which stretch from the northwest to the southwest and indicate the course taken by the inland-ice.

The right of the Saami population to hunt, fish and raise reindeer is enshrined in law. The park is used for reindeer herding during summer and winter, for migrating across Muddus/Muttos and for grazing of lichens.