ZIP Codes of Natrona County, WY

Population & People
Population & People
Total Population
79,937
Household Income
Household Income
Median Income
$67,263
Housing
Housing
Total Housing Units
37,300
Business & Economy
Business & Economy
Total Businesses
3,065
Employment
Employment
Employment Rate
63.55%
Education
Education
Bachelor's Degree+
27.61%
Source: U.S. Census ACS 2024 5-Year Estimates · rolled up across the 14 ZIPs in this county.
Data Last Updated: June 1, 2026
ZIP Codes:14 ZIP Codes (9 Standard, 5 PO Box, 0 Unique) [See All]
Area Code:307
Timezone:Mountain (GMT -07:00)
Local Time:2:14:25 PM
Population:79,937 [See All]
FIPS:56025
CBSA:Casper, WY
Land Area:5,344 sq mi
Water Area:25 sq mi
Coordinates:43.0061, -106.5902
Quick Link:
https://www.zip-codes.com/county/wy-natrona.asp
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Top 3 most populous in Wyoming
#2 of 28 counties in Wyoming, with 79,937 residents.

Standout ZIPs in this County


Most Populous
Casper · 27,487 people
34.4% of county total
Highest Income
Evansville · $86,638 median
1.3× county average
Largest Land Area
Casper · 1,814.9 sq mi
Spans the most ground
Fastest Growth
Mills · 35.4% (10-yr)
1,549 → 2,098 residents
Most Educated
Casper · 32.1% bachelor's+
4,066 of 12,679 adults 25+

Things worth knowing about Natrona County


79,937 residents live across 14 ZIPs covering 5,344 sq mi, served by 10 distinct USPS-recognized cities.

Population moved from 78,613 to 79,937 from 2014 to 2024 — a +1.7% change. 6 ZIPs gained residents, 5 lost (and 1 held flat).

The county's wealthiest ZIP 82636 (Evansville, $86,638 median) and poorest ZIP 82644 (Mills, $53,750) are 14.1 miles apart — a 1.6× income gap across local geography.

Median home values vary 1.7× across this county — from $175,900 in 82644 (Mills) to $299,300 in 82636 (Evansville).

Density varies 134× across the county — from 15 people/sq mi in 82604 (Casper) to 2,027 in 82644 (Mills).

Most of the decade's growth concentrated around Casper — top growth ZIPs averaged +15.9% over the past ten years ( 82644 , 82609 and 82604 ).

Educational attainment ranges from 12.9% bachelor's+ in 82644 (Mills) to 32.1% in 82609 (Casper) — the breadth of educational profiles across the area.

Within Wyoming, this is the #2 most populous of 28 counties and ranks #21 for median household income .

Weighted by population, the typical household earns about $73,043 across the county — reflecting what a typical resident sees, not a simple ZIP average.

27.6% of adults age 25+ hold a bachelor's degree or higher (15,136 of 54,820 reporting). The most-educated ZIPs cluster around Casper.

9 Standard delivery, 5 PO Box only, 0 single-entity Unique ZIPs serve this county.

Stories about Natrona County


Big & sparse

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.

Total area
5,344
square miles
Avg density
15.0
people per sq mi
Population
79,937
across 14 ZIPs
Casper
1,814.9 sq mi
27,487 residents
Alcova
1,088.7 sq mi
164 residents
Casper
801.1 sq mi
26,721 residents

All ZIP Codes in Natrona County


ZIPCityTypePopulationMedian IncomeArea (sq mi)10-yr Growth
82604CasperStandard27,487$79,1181,814.93.9%
82601CasperStandard26,721$67,642801.1-4.1%
82609CasperStandard18,714$71,010195.58.3%
82636EvansvilleStandard4,259$86,638132.43.6%
82644MillsPO Box2,098$53,7501.035.4%
82643MidwestStandard267$77,800208.7-55.9%
82620AlcovaStandard1641,088.7-32.5%
82638HilandStandard116377.1
82635EdgertonPO Box87$34,88644.3-78.3%
82648Powder RiverPO Box24103.984.6%
82630ArmintoStandard0391.3-100.0%
82646NatronaStandard0185.2
82605CasperPO Box0.0
82602CasperPO Box0.0

Adjacent & Nearby Counties