Largest Counties in Wyoming

Wyoming became a state in 1890 and is known for its wide-open spaces, including Yellowstone National Park. It has 23 counties.

10 Largest Counties in Wyoming

1. Laramie County

County Facts

  • Population: Approximately 105,000
  • Area Codes: 307
  • Zip Codes: 82001-82009
  • County Seat: Cheyenne

Geography and History

Laramie County is located in southeastern Wyoming and is known for its expansive plains and the Laramie Range. It is home to the state capital, Cheyenne, which is situated near the border with Colorado. Established in 1867, the county was named in honor of Jacques LaRamie, a French-Canadian fur trapper. The area played a significant role during the expansion of the railroad and was crucial in the development of the American West. Laramie County’s economy has historically been driven by agriculture, transportation, and government services. Today, it serves as a key administrative and economic center in the state.

Colleges and Universities

  • University of Wyoming: Located in Laramie, this flagship public university offers a wide range of undergraduate and graduate programs with strengths in engineering, business, and agriculture.
  • Cheyenne East High School: Provides specialized programs and advanced placement courses, preparing students for higher education and careers.

Major Landmarks

Laramie County boasts several significant landmarks that underscore its historical and cultural importance. The Wyoming State Capitol in Cheyenne, with its distinctive gold dome, is a major architectural landmark and the seat of state government. The Cheyenne Frontier Days, an annual rodeo and western celebration, highlights the county’s cowboy heritage and attracts visitors from across the country. The F.E. Warren Air Force Base, a key military installation, reflects the county’s strategic importance in defense. Additionally, the Cheyenne Depot Museum offers insights into the city’s railroad history. These landmarks showcase Laramie County’s blend of historical significance and modern development.


2. Natrona County

County Facts

  • Population: Approximately 85,000
  • Area Codes: 307
  • Zip Codes: 82601-82609
  • County Seat: Casper

Geography and History

Natrona County is located in central Wyoming, characterized by its diverse landscape of plains, mountains, and rivers. The county is named after Natrona Hill, a prominent geological feature in the area. Established in 1890, Natrona County has a history tied to the discovery of oil and natural gas, which has significantly influenced its economic development. Casper, the county seat, was founded as a key stop on the Union Pacific Railroad and has grown into a major center for energy production and transportation.

Colleges and Universities

  • Casper College: Offers a range of undergraduate programs with strengths in business, health sciences, and technology.
  • University of Wyoming (Casper College Branch): Provides additional educational opportunities and resources for students in central Wyoming.

Major Landmarks

Natrona County features several landmarks that reflect its historical and industrial significance. The National Historic Trails Interpretive Center in Casper provides exhibits on the westward expansion of the United States and the Oregon Trail. The Casper Mountain offers outdoor recreational opportunities, including hiking and skiing, with stunning views of the surrounding landscape. The Fort Casper Museum showcases the history of the military fort established during the Indian Wars. Additionally, the Casper Events Center hosts a variety of cultural and entertainment events. These landmarks highlight Natrona County’s rich history and its role in the region’s development.


3. Fremont County

County Facts

  • Population: Approximately 40,000
  • Area Codes: 307
  • Zip Codes: 82501-82520
  • County Seat: Lander

Geography and History

Fremont County is situated in west-central Wyoming, characterized by its mountainous terrain and expansive valleys. It is named after John C. Fremont, an explorer and military officer who mapped the western United States. Established in 1849, the county has a history tied to exploration, mining, and agriculture. The Wind River Range and the Bighorn Mountains are prominent geographical features, and the county is known for its rich Native American heritage, particularly the Shoshone and Arapaho tribes.

Colleges and Universities

  • Central Wyoming College: Located in Riverton, it offers a range of programs with strengths in agriculture, business, and liberal arts.
  • University of Wyoming (Extension Services): Provides educational resources and training related to agriculture, community development, and more.

Major Landmarks

Fremont County features several notable landmarks that highlight its historical and natural significance. The Wind River Indian Reservation, home to the Shoshone and Arapaho tribes, offers cultural and historical insights into Native American life. The Sinks Canyon State Park provides stunning natural scenery and opportunities for outdoor activities such as hiking and fishing. The South Pass City State Historic Site preserves a former gold mining town and offers a glimpse into the region’s mining history. Additionally, the Lander Pioneer Museum showcases local history and heritage. These landmarks reflect Fremont County’s blend of cultural heritage and natural beauty.


4. Sweetwater County

County Facts

  • Population: Approximately 44,000
  • Area Codes: 307
  • Zip Codes: 82901-82942
  • County Seat: Green River

Geography and History

Sweetwater County is located in southwestern Wyoming, characterized by its arid landscape and significant mineral resources. The county was established in 1867 and is named after the Sweetwater River, which flows through the area. The region has a history tied to mining, particularly in coal, oil, and natural gas, which have driven its economic development. Green River, the county seat, was founded as a transportation hub along the Union Pacific Railroad and remains an important center for industry and commerce.

Colleges and Universities

  • Western Wyoming Community College: Located in Rock Springs, it offers a variety of programs with strengths in technology, health sciences, and business.
  • University of Wyoming (Outreach Programs): Provides additional educational resources and opportunities for residents of southwestern Wyoming.

Major Landmarks

Sweetwater County features several landmarks that showcase its historical and industrial significance. The Rock Springs Historical Museum offers exhibits on the county’s mining history and pioneer life. The Green River Historic District includes preserved buildings that reflect the city’s early development as a railroad town. The Flaming Gorge National Recreation Area, partially extending into Sweetwater County, offers stunning landscapes and recreational activities such as boating and fishing. Additionally, the Sweetwater County Fairgrounds host a variety of local events and fairs. These landmarks highlight Sweetwater County’s rich industrial heritage and natural attractions.


5. Albany County

County Facts

  • Population: Approximately 40,000
  • Area Codes: 307
  • Zip Codes: 82070-82073
  • County Seat: Laramie

Geography and History

Albany County is located in southeastern Wyoming, known for its mountainous terrain and proximity to the Colorado border. Established in 1868, the county was named after Albany, New York. The county has a history tied to early settlement, agriculture, and its role as a gateway to the West. Laramie, the county seat, was founded as a key railroad town and is home to the University of Wyoming. The county’s geography includes parts of the Medicine Bow National Forest and the Laramie Range, offering a variety of outdoor recreational opportunities.

Colleges and Universities

  • University of Wyoming: Located in Laramie, it is the state’s flagship public university, offering a wide range of programs with strengths in engineering, business, and agriculture.
  • Laramie County Community College (Laramie Campus): Provides additional educational opportunities with a focus on career readiness and technical training.

Major Landmarks

Albany County features several landmarks that reflect its historical and natural significance. The University of Wyoming campus in Laramie is a major educational and cultural landmark, with historic buildings and research facilities. The Medicine Bow National Forest offers scenic landscapes and outdoor recreational activities, including hiking and camping. The Wyoming Territorial Prison State Historic Site in Laramie provides insights into early frontier law enforcement and prison life. Additionally, the Laramie Plains Museum showcases local history and heritage. These landmarks highlight Albany County’s role in education, history, and natural beauty.


6. Campbell County

County Facts

  • Population: Approximately 50,000
  • Area Codes: 307
  • Zip Codes: 82701-82732
  • County Seat: Gillette

Geography and History

Campbell County is located in northeastern Wyoming, characterized by its vast prairies and significant mineral resources. Established in 1911, the county was named after Campbell County, Kentucky. The region has a history closely tied to mining, particularly coal, which has driven its economic development. Gillette, the county seat, has grown rapidly as a major center for the coal industry and energy production. The county’s landscape includes parts of the Powder River Basin, one of the largest coal-producing regions in the United States.

Colleges and Universities

  • Gillette College: Offers a range of programs with strengths in health sciences, business, and technology.
  • University of Wyoming (Outreach Programs): Provides additional educational resources and opportunities for residents of northeastern Wyoming.

Major Landmarks

Campbell County features several landmarks that highlight its industrial and historical significance. The Rockpile Museum in Gillette offers exhibits on local history, including the region’s mining heritage. The Cam-Plex Multi-Event Facilities host a variety of events and community activities. The nearby Powder River Basin provides insights into the county’s coal mining history and offers recreational opportunities. Additionally, the Black Hills National Forest, located just to the east, provides scenic landscapes and outdoor activities. These landmarks reflect Campbell County’s industrial heritage and natural attractions.


7. Johnson County

County Facts

  • Population: Approximately 8,000
  • Area Codes: 307
  • Zip Codes: 82801-82837
  • County Seat: Buffalo

Geography and History

Johnson County is located in north-central Wyoming, characterized by its rolling hills and ranching landscape. Established in 1875, the county was named in honor of a prominent early settler. The county has a history tied to cattle ranching and early settlement, with Buffalo, the county seat, serving as a key center for agriculture and trade. The area’s geography includes parts of the Bighorn Mountains and the Powder River Basin, offering a mix of rugged terrain and open plains.

Colleges and Universities

  • Buffalo High School: Provides advanced placement courses and vocational training, preparing students for higher education and careers.
  • Sheridan College (nearby in Sheridan): Offers a range of programs with strengths in agriculture, business, and liberal arts.

Major Landmarks

Johnson County features several landmarks that highlight its rural charm and historical significance. The Buffalo Historic District includes preserved buildings and landmarks reflecting the county’s early settlement and ranching heritage. The Jim Gatchell Memorial Museum in Buffalo offers exhibits on local history and frontier life. Additionally, the nearby Bighorn Mountains provide stunning natural scenery and outdoor recreational opportunities. The Clear Creek Park offers a space for community events and outdoor activities. These landmarks showcase Johnson County’s blend of historical and natural attractions.


8. Sublette County

County Facts

  • Population: Approximately 9,000
  • Area Codes: 307
  • Zip Codes: 82901-82941
  • County Seat: Pinedale

Geography and History

Sublette County is located in western Wyoming, known for its mountainous terrain and expansive wilderness areas. Established in 1921, the county was named after William Sublette, a fur trader and explorer. The region has a history tied to the fur trade and exploration, with significant development occurring in the late 19th and early 20th centuries. The county’s geography includes parts of the Wind River Range and the Gros Ventre Range, offering a mix of rugged mountains and open valleys.

Colleges and Universities

  • Western Wyoming Community College (Pinedale Campus): Provides a range of programs with strengths in outdoor recreation, business, and liberal arts.
  • University of Wyoming (Outreach Programs): Offers additional educational resources and opportunities for residents of western Wyoming.

Major Landmarks

Sublette County features several landmarks that highlight its natural beauty and historical significance. The Wind River Range offers breathtaking landscapes and opportunities for outdoor activities such as hiking, camping, and fishing. The Pinedale Aquatic Center provides recreational facilities and community events. The Museum of the Mountain Man in Pinedale showcases the history of fur trappers and early explorers in the region. Additionally, the Green River provides scenic views and recreational opportunities. These landmarks reflect Sublette County’s blend of natural attractions and historical heritage.


9. Teton County

County Facts

  • Population: Approximately 24,000
  • Area Codes: 307
  • Zip Codes: 83001-83025
  • County Seat: Jackson

Geography and History

Teton County is located in northwestern Wyoming, known for its dramatic mountain scenery and outdoor recreation opportunities. Established in 1921, the county was named after the Teton Range, a prominent mountain range in the area. The county’s history is tied to early exploration and tourism, with Jackson, the county seat, serving as a gateway to Grand Teton National Park and Yellowstone National Park. The area’s geography includes rugged mountains, pristine lakes, and expansive forests.

Colleges and Universities

  • Jackson Hole Community School: Offers high-quality education with a focus on college preparation and outdoor education.
  • University of Wyoming (Jackson Outreach): Provides additional educational resources and opportunities for residents of Teton County.

Major Landmarks

Teton County features several landmarks that highlight its stunning natural beauty and outdoor recreation opportunities. Grand Teton National Park offers breathtaking mountain scenery, hiking trails, and opportunities for wildlife viewing. The Jackson Hole Historical Society and Museum provides insights into the area’s early history and development. The National Museum of Wildlife Art showcases a collection of wildlife-themed art set against a dramatic mountain backdrop. Additionally, the nearby Yellowstone National Park offers expansive geothermal features and diverse ecosystems. These landmarks reflect Teton County’s unique blend of natural wonders and cultural heritage.


10. Crook County

County Facts

  • Population: Approximately 7,000
  • Area Codes: 307
  • Zip Codes: 82716-82727
  • County Seat: Sundance

Geography and History

Crook County is located in northeastern Wyoming, characterized by its rolling hills and wide-open spaces. Established in 1875, the county was named after General George Crook, a prominent military officer. The county has a history tied to early settlement, ranching, and its role as a gateway to the Black Hills. Sundance, the county seat, has a historical connection to the railroad and cattle ranching, serving as a small but important center for local commerce and agriculture.

Colleges and Universities

  • Sundance High School: Provides advanced placement courses and vocational training for students preparing for higher education and careers.
  • Sheridan College (nearby in Sheridan): Offers a range of programs with strengths in agriculture, business, and liberal arts.

Major Landmarks

Crook County features several landmarks that reflect its historical and rural character. The Crook County Museum in Sundance offers exhibits on local history, including early settlement and ranching. The Sundance Historic District includes preserved buildings and landmarks that showcase the county’s early development. The nearby Black Hills provide scenic landscapes and recreational opportunities such as hiking and wildlife viewing. Additionally, the Wyoming-Montana State Line Monument marks the boundary between the two states. These landmarks highlight Crook County’s blend of historical significance and natural beauty.