Bannock County, Idaho

Bannock County is a county in Idaho, United States, in the southeastern part of the state along the Portneuf River. It had a population of 87,018 at the 2020 census and covers 1,112 square miles (2,880 km2) of land, centred near 42°40′N 112°13′W.

Pocatello is the county seat, and its postal code is 83201. The county has seven incorporated cities, two census-designated places and several unincorporated communities. Bannock County runs on Mountain Time and carries FIPS code 16005.

Towns & Villages in Bannock County

Eleven named places appear below: seven incorporated cities, two census-designated places (CDPs) and two unincorporated communities. Pocatello and Chubbuck, both in the northern Portneuf Valley, hold the great majority of the county’s population; the smaller cities line Interstate 15 and Interstate 86 to the south.

Fort Hall CDP sits on the Fort Hall Indian Reservation, home of the Shoshone-Bannock Tribes, and should not be confused with the historic Fort Hall trading post site nearby in Bingham County. Swan Lake and Downata Hot Springs are unincorporated communities without their own census counts; Downata Hot Springs is best known for the hot-springs resort just outside Downey.

ZIP Codes

• 83201 — Pocatello (also serves Tyhee)
• 83202 — Chubbuck
• 83203 — Fort Hall
• 83204 — Pocatello
• 83205 — Pocatello (PO Box)
• 83206 — Pocatello (PO Box)
• 83209 — Pocatello (Idaho State University, unique ZIP)
• 83214 — Arimo
• 83234 — Downey (also serves Downata Hot Springs)
• 83245 — Inkom
• 83246 — Lava Hot Springs
• 83250 — McCammon
• 83281 — Swan Lake (PO Box)

Pocatello alone carries six ZIP codes because of its size and Idaho State University’s dedicated code.

Geography

Bannock County sits in the Portneuf Valley of southeastern Idaho, a north-south corridor between the Bannock Range to the west and the Portneuf Range and Chesterfield Range to the east. The Portneuf River runs the length of the county before joining the Snake River system near American Falls. Elevations range from about 4,400 feet along the valley floor to over 9,000 feet in the surrounding mountains, and the county includes part of the Caribou-Targhee National Forest.

Bannock County borders Bingham County to the north, Power County to the west, Caribou County to the east, and Franklin County to the southeast. Oneida County lies to the southwest; townsvillages.com does not yet have a live page specific to Oneida County, Idaho.

Demographics

Bannock County had 87,018 residents at the 2020 census, a density of about 78 people per square mile. Pocatello (56,320) and Chubbuck (15,570) together hold more than four-fifths of the county’s population, with the remainder spread across the smaller Portneuf Valley cities and the Fort Hall Reservation. The county’s 2010-era median household income figure is stale; the current Idaho state median is $74,942 (2023 American Community Survey), and Bannock County’s own median has historically tracked close to the state figure given the mix of university, health-care and government employment in Pocatello.

Economy & Local Life

Idaho State University, headquartered in Pocatello, is the county’s largest single employer, alongside Portneuf Medical Center and the ON Semiconductor plant in Pocatello. State and federal government offices, the Union Pacific Railroad’s regional operations, and food-processing and warehousing tied to Interstate 15 and Interstate 86 round out the base. The Shoshone-Bannock Tribes operate the Shoshone-Bannock Casino Hotel and the Bannock Peak wind-energy resources on the Fort Hall Reservation. Lava Hot Springs, in the county’s south, is a long-running tourist town built around its mineral hot springs and summer whitewater on the Portneuf River.

History

Bannock County was organized on March 6, 1893, carved from Bingham and Oneida counties, and named for the Bannock people, who along with the Shoshone hold the adjacent Fort Hall Indian Reservation under an 1868 treaty. Pocatello grew up around a Union Pacific/Oregon Short Line rail junction in the 1880s and was named for Shoshone chief Pocatello, who negotiated the right-of-way through tribal land. The county’s history is bound up with the reservation boundary changes of the late 19th century, which repeatedly reduced tribal land to make way for the railroad and homesteaders.

Getting There

Interstate 15 runs north-south through the county, meeting Interstate 86 at Pocatello; US 30 and US 91 provide older parallel routes through the valley.

• Idaho Falls — 50 miles northeast
• Twin Falls — 90 miles west
• Salt Lake City, Utah — 165 miles south
• Boise — 230 miles west

Pocatello Regional Airport, on the city’s south side, offers commercial service; most longer-haul travelers connect through Salt Lake City International Airport.

Frequently Asked Questions

Where is Bannock County?
It is in southeastern Idaho, along the Portneuf River, centred on the city of Pocatello.

What is the population of Bannock County?
87,018 at the 2020 census, Idaho’s sixth-most-populous county.

How big is Bannock County?
1,112 square miles (2,880 km2) of land, plus 35 square miles (91 km2) of water.

What is the county seat of Bannock County?
Pocatello is the county seat and largest city.

How many towns are in Bannock County?
Seven incorporated cities, plus the Fort Hall and Tyhee census-designated places and a few unincorporated communities.

What ZIP codes are in Bannock County?
Thirteen ZIP codes, from 83201 (Pocatello) to 83281 (Swan Lake); see the ZIP Codes section above.

What tribal land is in Bannock County?
Part of the Fort Hall Indian Reservation, home of the Shoshone-Bannock Tribes, lies within the county’s northern edge.

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