Yuma is a city in and the county seat

County seat

A county seat is an administrative center, or seat of government, for a county or civil parish. The term is primarily used in the United States....

of Yuma County

Yuma County, Arizona

-2010:Whereas according to the 2010 U.S. Census Bureau:*70.4% White*2.0% Black*1.6% Native American*1.2% Asian*0.2% Native Hawaiian or Pacific Islander*3.8% Two or more races*20.8% Other races*59.7% Hispanic or Latino -2000:...

, Arizona

Arizona

Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...

, United States

United States

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

. It is located in the southwestern corner of the state, and the population of the city was 77,515 at 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...

, with a 2008 Census Bureau

United States Census Bureau

The United States Census Bureau is the government agency that is responsible for the United States Census. It also gathers other national demographic and economic data...

 estimated population of 90,041.

Yuma is the principal city of the Yuma, Arizona Metropolitan Statistical Area

Yuma metropolitan area

The Yuma Metropolitan Statistical Area, as defined by the United States Census Bureau, is an area consisting of a single county – Yuma – anchored by the city of Yuma...

, which consists of Yuma County. According to the United States Census Bureau

United States Census Bureau

The United States Census Bureau is the government agency that is responsible for the United States Census. It also gathers other national demographic and economic data...

, the 2008 estimated population of the Yuma MSA is 194,322, though more than 85,000 retirees make Yuma their winter residence.
The area's first settlers were Native American

Native Americans in the United States

Native Americans in the United States are the indigenous peoples in North America within the boundaries of the present-day continental United States, parts of Alaska, and the island state of Hawaii. They are composed of numerous, distinct tribes, states, and ethnic groups, many of which survive as...

 tribes whose descendants now occupy the Cocopah and Quechan

Quechan

The Quechan are a Native American tribe who live on the Fort Yuma Indian Reservation on the lower Colorado River in Arizona and California just north of the border with Mexico...

 reservations

Indian reservation

An American Indian reservation is an area of land managed by a Native American tribe under the United States Department of the Interior's Bureau of Indian Affairs...

.