Sugar Island is an island

Island

An island or isle is any piece of sub-continental land that is surrounded by water. Very small islands such as emergent land features on atolls can be called islets, cays or keys. An island in a river or lake may be called an eyot , or holm...

 in the U.S. state

U.S. state

A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...

 of Michigan

Michigan

Michigan is a U.S. state located in the Great Lakes Region of the United States of America. The name Michigan is the French form of the Ojibwa word mishigamaa, meaning "large water" or "large lake"....

 in the St. Marys River

St. Marys River (Michigan-Ontario)

The St. Marys River , sometimes written as the St. Mary's River, drains Lake Superior, starting at the end of Whitefish Bay and flowing 74.5 miles southeast into Lake Huron, with a fall of ....

 between the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 and the Canadian province of Ontario

Ontario

Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....

. The entire island constitutes Sugar Island Township

Sugar Island Township, Michigan

Sugar Island Township is a civil township of Chippewa County in the U.S. state of Michigan. The population was 683 at the 2000 census. The township consists, entirely, of Sugar Island in the St...

 in Chippewa County

Chippewa County, Michigan

-National protected areas:* Harbor Island National Wildlife Refuge* Hiawatha National Forest * Whitefish Point Unit of the Seney National Wildlife Refuge-Demographics:...

 at the eastern tip of the Upper Peninsula

Upper Peninsula of Michigan

The Upper Peninsula of Michigan is the northern of the two major land masses that make up the U.S. state of Michigan. It is commonly referred to as the Upper Peninsula, the U.P., or Upper Michigan. It is also known as the land "above the Bridge" linking the two peninsulas. The peninsula is bounded...

. According to the 2000 census

United States Census, 2000

The Twenty-second United States Census, known as Census 2000 and conducted by the Census Bureau, determined the resident population of the United States on April 1, 2000, to be 281,421,906, an increase of 13.2% over the 248,709,873 persons enumerated during the 1990 Census...

 there were 683 people living on a land area of 128 km² (49.4 sq mi).

The island lies between Lake George and Lake Nicolet, and to the north of Neebish Island

Neebish Island

Neebish Island is an island in the U.S. state of Michigan in the St. Marys River between the United States and the Canadian province of Ontario. It is divided into two parts known as "Big Neebish" and "Little Neebish" which are divided by a river which is sometimes more mud than river and is known...

 and St. Joseph Island

St. Joseph Island

St. Joseph Island is a Canadian island in Lake Huron, near the mouth of the St. Marys River which connects Lake Huron with Lake Superior. It is the second largest island in Lake Huron and the third largest in the Great Lakes overall, trailing Manitoulin and Lake Superior's Isle Royale.St...

. Pine Island

Pine Island (Ontario)

Pine Island is an island of Northern Ontario, Canada, in the northwestern portion of Lake Huron, near the mouth of the St. Marys River, which connects Lake Huron with Lake Superior. It has a mix of year-round and seasonal residents. Some of them live near the island; and some of those neighbors...

 is just east of its southern tip.

The island was part of the disputed US-Canadian border dispute settled by the Webster-Ashburton Treaty

Webster-Ashburton Treaty

The Webster–Ashburton Treaty, signed August 9, 1842, was a treaty resolving several border issues between the United States and the British North American colonies...

, and affirmed to be part of the United States when the treaty was signed August 9, 1842.

In 1945 Sugar Island was nominated a possible location for the headquarters of the United Nations

United Nations

The United Nations is an international organization whose stated aims are facilitating cooperation in international law, international security, economic development, social progress, human rights, and achievement of world peace...

.

The island has large undeveloped areas, and both the Bay Mills Indian Community

Bay Mills Indian Community

The Bay Mills Indian Community , known in Ojibwe as Gnoozhekaaning or Place of the Pike, is an Indian reservation forming the land base of one of the many Sault Ste. Marie bands of Chippewa Indians....

 and the Sault Tribe of Chippewa Indians

Sault Tribe of Chippewa Indians

The Sault Ste. Marie Tribe of Chippewa Indians of Michigan, commonly shortened to Sault Tribe of Chippewa Indians or the more colloquial Sault Tribe, is an indigenous community located in what is now known as Michigan's Upper Peninsula. The tribal headquarters is located within the major city in...

 have interests on the island. The Sault Tribe consider it to be part of their ancestral homelands.

The University of Michigan Biological Station

University of Michigan Biological Station

The University of Michigan Biological Station is a research and teaching facility operated by the University of Michigan. It is located on the south shore of Douglas Lake in Cheboygan County, Michigan. The station consists of 10,000 acres of land near Pellston, Michigan in the northern Lower...

operates the Chase Osborn Preserve, a 3200 acre (12.9 km²) tract near the southern tip of the island.