San Bernardino County is a county

County (United States)

In the United States, a county is a geographic subdivision of a state , usually assigned some governmental authority. The term "county" is used in 48 of the 50 states; Louisiana is divided into parishes and Alaska into boroughs. Parishes and boroughs are called "county-equivalents" by the U.S...

 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 California

California

California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

. As of the 2010 census, the population was 2,035,210, up from 1,709,434 as of the 2000 census. With an area of 20,105 square miles, San Bernardino County is the largest county in the contiguous United States

Contiguous United States

The contiguous United States are the 48 U.S. states on the continent of North America that are south of Canada and north of Mexico, plus the District of Columbia....

 by area, larger than any of the nine smallest states, and larger than the four smallest states combined; and larger than the closest-sized countries of Bosnia and Herzegovina

Bosnia and Herzegovina

Bosnia and Herzegovina , sometimes called Bosnia-Herzegovina or simply Bosnia, is a country in Southern Europe, on the Balkan Peninsula. Bordered by Croatia to the north, west and south, Serbia to the east, and Montenegro to the southeast, Bosnia and Herzegovina is almost landlocked, except for the...

 or Costa Rica

Costa Rica

Costa Rica , officially the Republic of Costa Rica is a multilingual, multiethnic and multicultural country in Central America, bordered by Nicaragua to the north, Panama to the southeast, the Pacific Ocean to the west and the Caribbean Sea to the east....

.

Located in southeast California, the thinly populated deserts and mountains of this vast county stretch from where the bulk of the county population resides, the roughly 480 square miles south of the San Bernardino Mountains in San Bernardino Valley

San Bernardino Valley

The San Bernardino Valley is a valley in Southern California. It lies at the south base of the Transverse Ranges. It is bordered on the north by the eastern San Gabriel Mountains and San Bernardino Mountains, on the east by the San Jacinto Mountains, and on the south and west by the Santa Ana...

, to the Nevada

Nevada

Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...

 border and the Colorado River.

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....

 is San Bernardino

San Bernardino, California

San Bernardino is a city located in the Riverside-San Bernardino metropolitan area , and serves as the county seat of San Bernardino County, California, United States...

.