Located in the upper northwest corner of the state, Box Elder County is part of the Great Basin and embraces a large land area extending from the west spur of the Wasatch Mountains to the Idaho border and westward to Nevada. It includes portions of the Great Salt Lake and the Great Salt Lake Desert. On the east are the lower course and deltas of the Bear River, the Malad River Valley, and the Promontory Mountains. Diverse in topography, the county contains rich farmlands as well as extensive marshlands at the mouth of the Bear River.

Prehistoric hunters and gatherers roamed the area as early as 12,000 years ago, as did Indians of later periods. Danger, Promontory, and Hogup Caves, surrounding Great Salt Lake, and Shallow Shelter in the Grouse Creek Mountains are among the important excavated archaeological sites in Box Elder.

During the 1820s and ’30s fur trappers, including Peter Skene Ogden and Joseph R. Walker, explored the eastern and northern parts of the county. Permanent white settlement began in 1851 when a group of Mormons took up land in North Willow Creek (Willard). Brigham City was settled that same year and under Lorenzo Snow’s direction became a model of Mormon cooperative enterprise. Because the land was already inhabited by Shoshone Indians, livestock raids and violent clashes between Indians and settlers were common until territorial Governor James Duane Doty negotiated the Treaty of Box Elder on July 30, 1863, in Brigham City.

In 1856 the territorial legislature created Box Elder County from part of Weber County. Its boundaries were redefined in 1880 when the legislature divided the water and islands of the Great Salt Lake among Salt Lake, Davis, Weber, Tooele, and Box Elder counties.

The most significant event in Box Elder history took place on May 10, 1869, at Promontory when the driving of the Golden Spike joined Central Pacific and the Union Pacific railroads to complete the transcontinental line. Corinne, a feisty, non-Mormon boomtown, became the freight transfer point for goods shipped to Idaho and Montana. In July 1870 Corinne residents spurred the founding of the Liberal party to oppose the Mormon People’s party.

Agriculture has always played an important role in the economy of Box Elder County. Some 43 percent of the county’s land is used for agricultural purposes. Besides the standard crops of hay, grain, and alfalfa, sugar beets were also raised, starting in 1901, and kept two sugar factories, one in Garland and the other in Brigham City, operating for many years. Abundant fruit orchards and garden crops continue to contribute to the local economy. Since 1957, when Thiokol Chemical (now Morton-Thiokol) began its Brigham City operation, defense and aerospace have dominated the local economy and presently employ 5,000. Morton-Thiokol built the Minuteman missile and the space shuttle booster rockets.