| ZIP Codes: | 8 ZIP Codes (8 Standard, 0 PO Box, 0 Unique) [See All] |
| Area Codes: | 208 / 986 |
| Timezone: | Mountain (GMT -07:00) |
| Local Time: | 2:11:57 PM |
| Population: | 33,524 [See All] |
| FIPS: | 16051 |
| CBSA: | Idaho Falls, ID |
| Land Area: | 1,436 sq mi |
| Water Area: | 14 sq mi |
| Coordinates: | 43.7773, -112.1300 |
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33,524 residents live across 8 ZIPs covering 1,436 sq mi, served by 8 distinct USPS-recognized cities.
Population moved from 27,068 to 33,524 from 2014 to 2024 — a +23.9% change. 5 ZIPs gained residents, 3 lost.
The county's wealthiest ZIP 83431 (Lewisville, $90,833 median) and poorest ZIP 83443 (Ririe, $65,590) are 22.4 miles apart — a 1.4× income gap across local geography.
Median home values vary 2.0× across this county — from $221,000 in 83435 (Monteview) to $449,300 in 83442 (Rigby).
Density varies 131× across the county — from 2 people/sq mi in 83435 (Monteview) to 273 in 83442 (Rigby).
Educational attainment ranges from 9.1% bachelor's+ in 83444 (Roberts) to 30.0% in 83442 (Rigby) — the breadth of educational profiles across the area.
Within Idaho, this is the #12 most populous of 46 counties and ranks #8 for median household income with the #9 fastest decade growth .
Weighted by population, the typical household earns about $86,072 across the county — reflecting what a typical resident sees, not a simple ZIP average.
27.1% of adults age 25+ hold a bachelor's degree or higher (5,383 of 19,827 reporting).
8 Standard delivery, 0 PO Box only, 0 single-entity Unique ZIPs serve this county.
A frontier county — vast land area with only a few residents per square mile. Daily life looks very different here than in the country's denser counties.
One ZIP holds the majority of this county's population — a sign of a county built around a single city or town.
| ZIP | City | Type | Population | Median Income | Area (sq mi) | 10-yr Growth |
|---|---|---|---|---|---|---|
| 83442 | Rigby | Standard | 25,609 | $88,260 | 93.7 | 30.7% |
| 83434 | Menan | Standard | 1,816 | $82,731 | 69.1 | -0.3% |
| 83443 | Ririe | Standard | 1,364 | $65,590 | 251.7 | 19.9% |
| 83444 | Roberts | Standard | 1,261 | $88,438 | 258.9 | -2.9% |
| 83450 | Terreton | Standard | 1,207 | $70,046 | 185.7 | 11.0% |
| 83431 | Lewisville | Standard | 1,045 | $90,833 | 12.7 | 15.9% |
| 83425 | Hamer | Standard | 622 | $80,833 | 277.5 | -23.4% |
| 83435 | Monteview | Standard | 600 | $73,750 | 286.8 | 44.2% |