Inuvialuit nations probably functioned much like those of their better documented western neighbours, the Inupiat (as the Inuit or Eskimo of northwestern Alaska are called). Here each karigi was built and operated by a single large extended family, often numbering fifty or more people. Each had a family head or chief known as an ataniq, or "boss." A successful, wealthy ataniqwas called an umialiq, a "rich man."
Among both the Inupiat and the Inuvialuit such leadership positions depended very much on the skill, generosity, and family connections of the individual involved. Inuvialuit kinship rules were flexible and included people related by marriage as well as those related by blood. The more successful and the more generous an ataniq (or umialiq), the larger the extended family he headed could become, as more people chose to join it. By the same token, a successful umialiq (or ataniq) was not merely shrewd and personally competent, he was someone with a large potential following; a man with many relatives. There was thus a tendency for the office to be hereditary, since a capable oldest son could sometimes step into his father's shoes. If the umialiq managed the family well it prospered, and as long as it prospered he naturally had first call on the wealth produced. This wealth resulted both from the hunt and from inter-regional trade, which was largely controlled by umialit (the plural form). On the other hand, an unsuccessful umialiq could easily lose his following.
Their powers were sometimes considerable. The missionary Whittaker described a "strange Eskimo" moving into Kittigazuit who had to make a payment to the "chief" in order to be able to hunt. Similarly, it was reported that umialit had the power to boycott trade with whaling ships, and to demand a payment of whaling captains who wished to hire "their" people. Mangilaluk, who lived at Tuktoyaktuk and died in 1940, is generally considered to be the last true umialiq in Inuvialuit tradition.