The area has a short growing season, cold winters, little precipitation and poor soil quality created by the gneiss bedrock.

Lake Inari has been affected by acid rain and loss of fish from the Paatsjoki River Hydroelectric Plants.

The reserve is an important habitat of the brown bear and also has a large moose population; reindeer husbandry is practiced by the Samis.

The wilderness area is located on the northeastern shore of Lake Inari and extends northeastwards into a treeless fell ridge.

The landscape consists of taiga forests of Scots pine in the lower areas, bog, thousands of small lakes, and creeks.

Construction of the Paatsjoki River Hydroelectric Plants has changed the hydrology considerably, providing for a more stable regulation of Lake Inari, but reducing the flow speed.

The Inari Basin was created after the last glacial period when an ice blockage in the Pasvik River hindered the draining of melted water in the area.

[6] Some lakes in the eastern part of the Wilderness are damaged by acid rain from the Norilsk Nickel plant in Nikel, Russia.

[8] The area was populated in the Stone Age by Inari Sami people shortly after the last glacial period ended about 8000 BC.

[9] The Inari Sami originally subsisted on hunting, gathering and especially fishing; later they began to complement this by reindeer husbandry, and later still by farming and herding cattle and sheep.

People in the area traveled up Lake Inari and onwards to the coast of Finnmark, Norway, to fish during summer.

Records of markets in Finnmark date back to the 16th century, and in the 1880s about 150 people traveled to the coast each year.

Other predators include red fox, stoat, pine marten and the rare wolverine and Eurasian lynx.

The reserve is located in an area between a western and eastern vegetation zones, giving rise to unique combinations of species, such as Siberian spruce and red cottongrass.

[7] Most recreation takes place around Lake Inari, although a limited number of visitors hike into the fells.