Box Elder County, Utah

Box Elder County is a county in Utah, United States, on the state’s northern border with Idaho and its western border with Nevada. It had a population of 57,666 at the 2020 census and covers roughly 6,680 square miles (17,300 km2) of land and water, centred near 41°31′N 113°06′W.

Brigham City is the county seat, and its postal code is 84302. The county has 8 incorporated cities, 8 incorporated towns and a scatter of unincorporated communities and historic railroad-era settlements west of the Great Salt Lake. Box Elder County has no civil townships. It sits in the Mountain time zone and carries FIPS code 49003.

Towns & Villages in Box Elder County

The table below lists every place carried over from Box Elder County’s community list, split between incorporated cities and towns in the settled Bear River Valley in the county’s east, and the unincorporated and historic places scattered across the arid Great Salt Lake Desert and Raft River Mountains to the west. Population figures are omitted where no verified 2020 count is available.

Several of these are historic Central Pacific Railroad sidings and section-house stops built for the transcontinental railroad, which crossed the county’s western desert through Kelton, Lucin, Rozel, Matlin and Terrace before the Lucin Cutoff bypassed the route in 1904 — most exist today as a rail sign and a few foundations, not an active settlement. Promontory Summit, where the golden spike joined the Union Pacific and Central Pacific lines in 1869, is preserved as Golden Spike National Historical Park rather than a town.

ZIP Codes

• 84302 — Brigham City
• 84337 — Tremonton
• 84312 — Garland
• 84340 — Willard
• 84324 — Mantua
• 84307 — Corinne
• 84311 — Fielding
• 84314 — Honeyville
• 84301 — Bear River City
• 84309 — Deweyville
• 84306 — Collinston (also serves Portage-area farms in the far north)
• 84336 — Snowville
• 84329 — Park Valley
• 84330 — Plymouth
• 84316 — Howell
• 84331 — Portage
• 84334 — Riverside
• 84313 — Grouse Creek

Perry, Elwood, South Willard and Thatcher have no ZIP code of their own and are served by the Brigham City or Tremonton post offices depending on which is closer.

Geography

Box Elder County spans two very different landscapes. Its eastern strip, the Bear River Valley, is irrigated farmland squeezed between the Wasatch Range and the northeast arm of the Great Salt Lake. West of the lake the county opens into the Great Salt Lake Desert, a stretch of salt flats and playas broken by the Raft River Mountains, Grouse Creek Mountains and Newfoundland Mountains near the Nevada line. The Bear River, the largest river to feed the Great Salt Lake without ever leaving it, crosses the settled eastern part of the county past Corinne and Bear River City.

Box Elder County borders four counties and two states. To the north, across the Idaho line, are Cassia County, Idaho and Oneida County, Idaho. To the east is Cache County, and southeast is Weber County. To the south, across the Great Salt Lake, is Davis County, and south-southeast is Tooele County. To the west, across the Nevada line, is Elko County, Nevada.

Demographics

Box Elder County had 57,666 residents at the 2020 census. Brigham City and Tremonton are its two largest communities by far, together holding roughly half the county’s population; nearly all the rest lives in the smaller Bear River Valley cities and towns strung along US-89 and US-30 between them. County-level median household income data from the 2020 census put the figure near $63,600, below the Utah state median of $93,421 in the 2023 American Community Survey — a gap that reflects the county’s large agricultural and rural share compared with the Wasatch Front metro counties to the south. Population density is low outside the valley, since more than half the county’s land area is sparsely inhabited desert and mountain range.

Economy & Local Life

Agriculture anchors the Bear River Valley economy — dairy, sugar beets, alfalfa and grain around Tremonton, Garland and Corinne — alongside food processing tied to that farm output. Brigham City is home to Hill Air Force Base’s ICBM Systems Directorate campus and to a cluster of aerospace and defense contractors that grew up around Thiokol’s (now Northrop Grumman’s) solid-rocket-motor plant near Promontory, one of the county’s largest private employers. Utah State University operates a Brigham City regional campus. Golden Spike National Historical Park at Promontory Summit draws visitors for the annual Golden Spike re-enactment each May, marking the 1869 completion of the transcontinental railroad.

History

Box Elder County was created by the Utah Territorial Legislature on January 5, 1856, carved out of the original Weber County. It takes its name from the box elder trees that grew along Box Elder Creek where Brigham City was settled by Mormon pioneers beginning in 1851. The county’s defining historical moment came on May 10, 1869, when the Union Pacific and Central Pacific railroads met at Promontory Summit to complete the first transcontinental railroad; the original route through the county’s western desert was largely abandoned after the Lucin Cutoff trestle across the Great Salt Lake opened in 1904, leaving Kelton, Lucin, Rozel and other siding towns to fade.

Getting There

Interstate 15 runs north-south through the settled eastern part of the county, linking Brigham City and Tremonton to Ogden and Salt Lake City to the south and to southern Idaho to the north. US-30 and US-83 serve the more remote western communities toward the Nevada line.

• Ogden — 20 miles south of Brigham City
• Salt Lake City — 55 miles south of Brigham City
• Logan — 25 miles east of Brigham City
• Twin Falls, Idaho — 65 miles north of Tremonton

The nearest commercial airport is Salt Lake City International Airport, roughly an hour’s drive south of Brigham City via I-15.

Frequently Asked Questions

Where is Box Elder County?
It is in the far northwestern corner of Utah, bordering Idaho to the north and Nevada to the west, on the northern shore of the Great Salt Lake.

What is the population of Box Elder County?
57,666 people, per the 2020 census.

How big is Box Elder County?
It covers about 6,680 square miles (17,300 km2) of land and water, making it one of the largest counties in Utah by area.

What is the county seat of Box Elder County?
Brigham City is the county seat and largest city.

How many towns and cities are in Box Elder County?
Eight incorporated cities and eight incorporated towns, plus three census-designated places and a number of unincorporated and historic settlements.

What ZIP codes are in Box Elder County?
Eighteen ZIP codes serve the county, from 84302 in Brigham City to 84313 in Grouse Creek; see the ZIP Codes section above for the full list.

What is Golden Spike National Historical Park?
It is the National Park Service site at Promontory Summit marking the spot where the transcontinental railroad’s two halves joined in 1869; it is not an active town, though it sits inside the historic Promontory community.

More counties in this state: Towns and villages in Utah.