Fremont County is a county in Iowa, United States, in the state’s southwest corner along the Missouri River. It had a population of 6,605 at the 2020 census and covers 517 square miles (1,340 km2) centred near 40°44′N 95°37′W.
Sidney is the county seat, and its postal code is 51652. The county contains nine incorporated cities and six unincorporated communities. Fremont County lies in the Central time zone and carries FIPS code 19071.
Towns & Villages in Fremont County
Fremont County has 15 named places on the map: nine incorporated cities, including the county seat, and six unincorporated communities with no municipal government of their own. Each of the nine cities has its own ZIP code; the unincorporated communities are served by the nearest post office.
| Place | Type | Pop. | ZIP |
|---|---|---|---|
| Sidney | City · seat | 1,070 | 51652 |
| Tabor | City | 928 | 51653 |
| Hamburg | City | 890 | 51640 |
| Farragut | City | — | 51639 |
| Randolph | City | — | 51649 |
| Riverton | City | — | 51650 |
| Thurman | City | — | 51654 |
| Percival | City | — | 51648 |
| Imogene | City | — | 51645 |
| Anderson | Unincorp. | — | — |
| Bartlett | Unincorp. | — | — |
| High Creek | Unincorp. | — | — |
| McPaul | Unincorp. | — | — |
| Payne | Unincorp. | — | — |
| Summit | Unincorp. | — | — |
ZIP Codes
- 51652 — Sidney
- 51653 — Tabor
- 51640 — Hamburg
- 51639 — Farragut
- 51645 — Imogene
- 51648 — Percival
- 51649 — Randolph
- 51650 — Riverton
- 51654 — Thurman
Anderson, Bartlett, High Creek, McPaul, Payne and Summit have no post office of their own and are served by the ZIP code of the nearest incorporated town.
Geography
Fremont County sits on the Loess Hills above the Missouri River floodplain, in Iowa’s far southwest corner. Of its 517 square miles, 511 are land and 5.5 are water. The Missouri River forms most of the county’s western edge, and the Nishnabotna River crosses the county before joining it. The lowland along the river has flooded repeatedly, including a prolonged 2019 event that put much of the western county underwater for months.
Fremont County borders Mills County to the north and Page County to the east, both in Iowa. To the south lies Atchison County, Missouri. Across the Missouri River to the west lies Nebraska.
Demographics
Fremont County had 6,605 residents at the 2020 census, giving it a density of roughly 13 people per square mile — one of the more sparsely populated counties in Iowa. Sidney and Tabor are the two largest communities, at 1,070 and 928 residents respectively. Statewide, the Iowa median of $71,433 sets the benchmark for household income; incomes in Fremont County’s farm-dependent towns typically run below that figure.
Economy & Local Life
Row-crop farming — corn and soybeans on the county’s bottomland and rolling loess uplands — anchors the local economy, alongside livestock operations and the grain elevators and farm-supply businesses that serve them. Sidney is home to the Fremont County Fair, one of the longer-running county fairs in southwest Iowa, held each August at the county fairgrounds. Local schools, county government offices and small-town retail round out employment in the county seat and the smaller cities.
History
Fremont County was organized in 1847 and named for John C. Frémont, the U.S. Army officer and explorer known for his expeditions through the American West. Tabor, founded by anti-slavery Congregationalist settlers in the 1850s, became a documented stop on the Underground Railroad and later hosted John Brown as he trained men before his raid on Harpers Ferry. The county’s river towns have weathered repeated Missouri River flooding, most severely in 2019, and a damaging hailstorm struck the area on April 17, 2025.
Getting There
Interstate 29 runs north–south along the county’s western edge near the Missouri River, and Iowa Highway 2 crosses the county east–west through Sidney, Hamburg and Tabor. The nearest commercial airport is Eppley Airfield in Omaha, Nebraska, roughly 45 miles to the northwest.
- Hamburg — 10 miles southwest of Sidney
- Tabor — 12 miles north of Sidney
- Farragut — 8 miles east of Sidney
- Omaha, Nebraska — about 45 miles northwest of Sidney
Frequently Asked Questions
Where is Fremont County, Iowa?
It sits in the far southwest corner of Iowa, along the Missouri River, bordering both Nebraska and Missouri.
What is the population of Fremont County?
Fremont County had a population of 6,605 at the 2020 census.
How big is Fremont County?
The county covers 517 square miles (1,340 km2), of which 511 square miles are land.
What is the county seat of Fremont County?
Sidney is the county seat.
How many towns are in Fremont County?
The county has nine incorporated cities — Sidney, Tabor, Hamburg, Farragut, Randolph, Riverton, Thurman, Percival and Imogene — plus six unincorporated communities.
What ZIP codes are in Fremont County?
Fremont County’s ZIP codes are 51652 (Sidney), 51640 (Hamburg), 51653 (Tabor), 51639 (Farragut), 51645 (Imogene), 51648 (Percival), 51649 (Randolph), 51650 (Riverton) and 51654 (Thurman).
Who is Fremont County named after?
The county is named for John C. Frémont, the U.S. Army officer and explorer.
More counties in this state: Towns and villages in Iowa.