This area was the territory of Western Shoshone, Northern Paiute, and Bannock peoples and their ancestors for thousands of years prior to the arrival of European settlers.

Settler interests in securing land and resources spurred conflict and led to the indigenous peoples being forced onto reservations.

[8] Owyhee County's original boundary was the portion of Idaho Territory south of the Snake River and west of the Rocky Mountains.

Owyhee County's history is closely linked to the mining boom that dominated Idaho Territory in the second half of the 19th century.

In the 20th century, the tribes combined and are federally recognized as a single government; the majority of the people live on the Nevada side of the reservation.

In 1997, Union Pacific filed for permission to abandon the Idaho portion of the line and received no formal protest, the tracks were ripped up the following year.

[12] In 1934, the county seat was moved from the nearly abandoned Silver City to its present location in Murphy.

Noted for their hardy physique and maritime skills, numerous Native Hawaiians were hired as crew members aboard European and American vessels.

Many Native Hawaiians sailed to the American Northwest coast and found employment along the Columbia River, where they joined trapping expeditions or worked at some of the fur trading posts.

The three Hawaiians left the main party during the winter of 1819–1820 to explore the then unknown terrain of what since has been called the Owyhee River and mountains.

In memory of these Native Hawaiians, British fur trappers started to call the region "Owyhee" and the name stuck.

The Owyhee Mountains in the west dominate the landscape, with Hayden Peak reaching 8,403 feet (2,561 m) above sea level.

The lowest elevation is at the county's northwest corner, where the Snake River is just above 2,000 feet (610 m) at the Oregon border.

A tributary of the Snake is the Bruneau River, which flows north from Nevada through the eastern section of the county.

The Owyhee River starts in the southwestern part of the county and flows westward into Oregon; it eventually enters the Snake at the state border, south of Nyssa.

[26] Although Owyhee County was amongst the most Democratic in the state in its early history, it has like most of Idaho gradually turned overwhelmingly Republican.

[citation needed] School districts include:[28] Residents in a portion of the county are in the area (but not the taxation zone) for College of Western Idaho.