The data on units in structure (also referred to as "type of structure") were obtained from Housing Question 1 in the 2007 American Community Survey. The question was asked at occupied and vacant housing units. A structure is a separate building that either has open spaces on all sides or is separated from other structures by dividing walls that extend from ground to roof. In determining the number of units in a structure, all housing units, both occupied and vacant, are counted. Stores and office space are excluded. The data are presented for the number of housing units in structures of specified type and size, not for the number of residential buildings.

A person having origins in any of the original peoples of North and South America (including Central America) and who maintain tribal affiliation or community attachment. It includes people who classified themselves as described below.
American Indian -This category includes people who indicate their race as "American Indian," entered the name of an Indian tribe, or reported such entries as Canadian Indian, French American Indian, or Spanish American Indian.
American Indian Tribe -Respondents who identified themselves as American Indian were asked to report their enrolled or principal tribe. Therefore, tribal data in tabulations reflect the written entries reported on the questionnaires. Some of the entries (for example, Iroquois, Sioux, Colorado River, and Flathead) represent nations or reservations. The information on tribe is based on self-identification and therefore does not reflect any designation of a federally- or state-recognized tribe. The information for the American Community Survey is derived from the American Indian Tribal Classification List for the 1990 census that was updated for Census 2000 and the ACS based on a December 1997Federal Register Notice entitled "Indian Entities Recognized and Eligible to Receive Service From the United States Bureau of Indian Affairs," Department of the Interior, Bureau of Indian Affairs, issued by the Office of Management and Budget.
Alaska Native - This category includes written responses of Eskimos, Aleuts, and Alaska Indians as well as entries such as Arctic Slope, Inupiat, Yupik, Alutiiq, Egegik, and Pribilovian. The Alaska tribes are the Alaskan Athabascan, Tlingit, and Haida. The information for ACS is based on the American Indian Tribal Classification List for the 1990 census and Census 2000, which was expanded to list the individual Alaska Native Villages when provided as a written response for race.

The data on relationship to householder were derived from answers to Question 3, which was asked of all people in housing units. One person in each household is designated as the householder. In most cases, this is the person, or one of the people, in whose name the home is owned, being bought, or rented and who is listed on line one of the survey questionnaire. If there is no such person in the household, any adult household member 15 years old and over could be designated as the householder. Households are classified by type according to the sex of the householder and the presence of relatives. Two types of householders are distinguished: a family householder and a non-family householder. A family householder is a householder living with one or more individuals related to him or her by birth, marriage, or adoption. The householder and all people in the household related to him or her are family members. A non-family householder is a householder living alone or with non-relatives only.