Nunivak Island in the context of Yupʼik

The Yupʼik or Yupiaq (sg & pl) and Yupiit or Yupiat (pl), also Central Alaskan Yupʼik, Central Yupʼik, Alaskan Yupʼik (own name Yupʼik sg Yupiik dual Yupiit pl; Russian: Юпики центральной Аляски), are an Indigenous people of western and southwestern Alaska ranging from southern Norton Sound southwards along the coast of the Bering Sea on the Yukon-Kuskokwim Delta (including living on Nelson and Nunivak Islands) and along the northern coast of Bristol Bay as far east as Nushagak Bay and the northern Alaska Peninsula at Naknek River and Egegik Bay. They are also known as Cupʼik by the Chevak Cupʼik dialect-speaking people of Chevak and Cupʼig for the Nunivak Cupʼig dialect-speaking people of Nunivak Island.

The Yupiit are the most numerous of the various Alaska Native groups and speak the Central Alaskan Yupʼik language, a member of the Eskimo–Aleut family of languages. As of the 2010 U.S. Census, the Yupiit population in the United States numbered over 34,000 people, of whom over 22,000 lived in Alaska. The vast majority of these live in the seventy or so communities in the traditional Yupʼik territory of western and southwestern Alaska. About 10,000 speak the language. The Yupʼik had the greatest number of people who identified with one tribal grouping and no other race (29,000). In that census, nearly half of American Indians and Alaska Natives identified as being of mixed race.

St. Matthew Island (Russian: Остров Святого Матвея, romanized: Ostrov Svyatogo Matveya) is an uninhabited, remote island in the Bering Sea in Alaska, 183 miles (295 km) west-northwest of Nunivak Island. The entire island's natural scenery and wildlife is protected as it is part of the Bering Sea unit of the Alaska Maritime National Wildlife Refuge and as the Bering Sea Wilderness.

The island has a land area of 137.857 sq mi (357.05 km), making it the 44th largest island in the United States. Its most southerly point is Cape Upright which features cliff faces which exceed 1,000 feet (300 m). Similar heights are found at Glory of Russia Cape on the north, and the highest point, 1,476 feet (450 m) above sea level, lies south from the island center.

Nelson Island (Central Yupik: Qaluyaaq) is an island in the Bethel Census Area of southwestern Alaska. It is 42 miles (68 km) long and 20–35 miles (32–56 km) wide. With an area of 843 square miles (2,183 km), it is the 15th largest island in the United States. It is separated from the Alaska mainland to its north by the Ningaluk River, to its east by the Kolavinarak River and from Nunivak Island to its southwest by the Etolin Strait.

Nelson Island has four permanent communities along its coast:

Chevak Cupʼik or just Cupʼik (and sometimes Cugtun) is a subdialect of the Hooper Bay–Chevak dialect of Yupʼik spoken in southwestern Alaska in the Chevak (Cupʼik, Cevʼaq) by Chevak Cupʼik Eskimos (own name Cupʼit or Cevʼallrarmuit). Speakers of the Chevak subdialect refer to themselves as Cupʼik (as opposed to Yupʼik), while speakers of the Hooper Bay subdialect refer to themselves as Yupʼik (not Cupʼik), as in the Yukon-Kuskokwim dialect.

The Central Alaskan Yupik who live in the village of Chevak call themselves Cupʼik (plural Cupʼit), whereas those who live on Nunivak Island (Nuniwar in Nunivak Cupʼig, Nunivaaq in Central Yupʼik) call themselves Cupʼig (plural Cupʼit), the spelling differences serving as a self-designated cultural identifier between the two groups. In both dialects, the Yupʼik consonant c is pronounced as an English ch. The Cupʼik dialect is readily distinguished from other dialects of Yupʼik by the pronunciation of the Yupʼik "y" sound as a "ch" sound (represented by the letter "c"), and by some fundamental differences in the basic vocabulary.

Nunivak Cup'ig or just Cup'ig (own name Cugtun) is a language or separate dialect of Central Alaskan Yup'ik spoken in Central Alaska at the Nunivak Island by Nunivak Cup'ig people (own name Cup'it or Nuniwarmiut). The letter "c" in the Yup’ik alphabet is equivalent to the English alphabet "ch".

The Central Alaskan Yupik who live on Nunivak Island (Nuniwar in Nunivak Cup'ig, Nunivaaq in Central Yup'ik) call themselves Cup'ig (plural Cup'it). Those who live in the village of Chevak call themselves Cup'ik (plural Cup'it). The name Cup'ig (with g) is used for the Nunivak Island Yup'ik dialect and the name Cup'ik (with k) is used for Hooper Bay-Chevak Yup'ik dialect.