Wyoming Counties. List Alphabetically (and by Population)
How many counties are there in Wyoming? As of 2024, there are a total of 23 counties in the state of Wyoming. Among them, Laramie County is the oldest one (established in 1867) while Teton County is the youngest (established in 1921). With population of 94,483, Laramie County is the most populated. The biggest county by land area is Sweetwater County (27,003 km²) and the smallest is Hot Springs County (5,190 km²).
Largest Counties in Wyoming
1. Sweetwater County
County Overview
- County Seat: Green River
- Area: 10,491 square miles
- Population: 42,343 (2020 Census)
- Area Codes: 307
- Latitude: 41.7484° N
- Longitude: 109.2025° W
Location and History
Sweetwater County, located in southwestern Wyoming, is the largest county in the state by area. The county was established in 1867 and named after the Sweetwater River, which runs through the area. The region played a pivotal role in the westward expansion of the United States, serving as a key location on the Oregon Trail, the California Trail, and the Mormon Trail. The arrival of the Union Pacific Railroad in the late 1860s further spurred development, particularly in the towns of Green River and Rock Springs. The county’s economy has historically been driven by coal mining, oil extraction, and trona production, making it a vital industrial hub in Wyoming.
Major Highways and Landmarks
Sweetwater County is intersected by major highways, including Interstate 80, which runs east-west across the county, providing a critical transportation route. U.S. Route 191 is another significant highway that traverses the region. Major landmarks in the county include the Flaming Gorge National Recreation Area, known for its stunning reservoir and scenic vistas, and the historic South Pass, a critical point on the Oregon Trail. The Killpecker Sand Dunes, one of the largest active sand dune fields in North America, is also a notable natural feature in the county.
2. Carbon County
County Overview
- County Seat: Rawlins
- Area: 7,964 square miles
- Population: 14,537 (2020 Census)
- Area Codes: 307
- Latitude: 41.7919° N
- Longitude: 106.9630° W
Location and History
Carbon County, located in south-central Wyoming, was established in 1868. The county was named after the rich coal deposits found in the area, which were extensively mined during the 19th and early 20th centuries. Rawlins, the county seat, was a crucial stop on the Union Pacific Railroad, contributing to the county’s early development. The history of Carbon County is also marked by its role in the westward migration, with the Overland Trail passing through the region. The county’s economy has traditionally relied on mining, ranching, and, more recently, tourism, thanks to its vast wilderness areas and outdoor recreation opportunities.
Major Highways and Landmarks
Interstate 80 and U.S. Route 30 are the primary highways crossing Carbon County, facilitating travel and commerce. The county is home to several significant landmarks, including the Medicine Bow-Routt National Forests, offering a variety of recreational activities such as hiking, camping, and fishing. The Seminoe State Park, with its reservoir and scenic surroundings, is another popular destination. Additionally, the historic Sinclair Refinery, one of the oldest oil refineries in Wyoming, reflects the county’s long-standing connection to the energy industry.
3. Fremont County
County Overview
- County Seat: Lander
- Area: 9,266 square miles
- Population: 39,234 (2020 Census)
- Area Codes: 307
- Latitude: 43.0000° N
- Longitude: 108.9007° W
Location and History
Fremont County, situated in central Wyoming, was established in 1884 and named after John C. Frémont, an explorer and politician known as “The Pathfinder.” The county is known for its diverse geography, which includes the Wind River Range, the Absaroka Mountains, and the Wind River Valley. The Shoshone National Forest, one of the oldest national forests in the United States, is located within the county. The county’s history is deeply tied to the Native American tribes of the region, particularly the Eastern Shoshone and Northern Arapaho, who reside on the Wind River Indian Reservation, which occupies a significant portion of the county.
Major Highways and Landmarks
Major highways in Fremont County include U.S. Route 26 and U.S. Route 287, both of which provide access to some of the county’s most stunning landscapes. The Wind River Canyon is a notable natural landmark, offering breathtaking views along the highway. The Sinks Canyon State Park, where the Popo Agie River disappears into a cavern and re-emerges a quarter-mile downstream, is a unique geological feature and a popular tourist attraction. Additionally, the historic South Pass City, a well-preserved ghost town from the gold rush era, offers a glimpse into the region’s mining history.
4. Natrona County
County Overview
- County Seat: Casper
- Area: 5,340 square miles
- Population: 79,955 (2020 Census)
- Area Codes: 307
- Latitude: 42.8666° N
- Longitude: 106.3131° W
Location and History
Natrona County is located in central Wyoming and was established in 1888. It was named after the large deposits of natron, a type of sodium carbonate, found in the area. Casper, the county seat, is the second-largest city in Wyoming and a major hub for energy production, particularly oil and natural gas. The county’s history is marked by the development of the oil industry, with the first oil well drilled near Salt Creek in 1889. This discovery led to a boom in oil production, making Casper a key center for the industry. The county’s economy continues to be driven by energy production, as well as healthcare, education, and retail.
Major Highways and Landmarks
Interstate 25 is the primary highway running through Natrona County, connecting Casper to other major cities in Wyoming and beyond. U.S. Route 20 also passes through the county, providing access to various destinations. The county is home to several major landmarks, including the National Historic Trails Interpretive Center, which offers exhibits on the Oregon Trail, the California Trail, and the Mormon Trail. Casper Mountain, located just south of the city of Casper, is a popular recreational area with hiking trails, ski slopes, and scenic vistas. The Alcova Reservoir, another key attraction, offers opportunities for boating, fishing, and camping.
5. Park County
County Overview
- County Seat: Cody
- Area: 6,967 square miles
- Population: 29,624 (2020 Census)
- Area Codes: 307
- Latitude: 44.4066° N
- Longitude: 109.5167° W
Location and History
Park County, located in northwestern Wyoming, was established in 1909 and named for Yellowstone National Park, part of which lies within the county’s boundaries. The county seat, Cody, was founded by the legendary showman and scout William “Buffalo Bill” Cody in 1896. The town quickly became a gateway to Yellowstone and a center for tourism in the region. The county’s history is closely tied to the development of the American West, with Cody playing a significant role in promoting the frontier spirit and attracting visitors from across the country. Today, tourism remains a vital part of the county’s economy, along with agriculture and energy production.
Major Highways and Landmarks
U.S. Routes 14, 16, and 20 are the main highways that traverse Park County, providing access to Yellowstone National Park and other scenic areas. Major landmarks in the county include the Buffalo Bill Center of the West, a world-renowned museum complex dedicated to the history and culture of the American West. The Beartooth Highway, one of the most scenic drives in the United States, offers breathtaking views of the Beartooth Mountains and leads into Yellowstone. The Shoshone National Forest, another key landmark, provides a vast wilderness area for outdoor activities such as hiking, camping, and wildlife viewing.
6. Teton County
County Overview
- County Seat: Jackson
- Area: 4,216 square miles
- Population: 23,464 (2020 Census)
- Area Codes: 307
- Latitude: 43.7904° N
- Longitude: 110.6818° W
Location and History
Teton County, located in northwestern Wyoming, was established in 1921 and named after the Teton Range, a prominent mountain range within the county. The county seat, Jackson, is a well-known destination for tourists, outdoor enthusiasts, and those seeking a connection to nature. The region’s history is rooted in the fur trade, with early explorers and trappers venturing into the area in the early 19th century. The establishment of Grand Teton National Park in 1929 and the subsequent development of the Jackson Hole ski resort further solidified the county’s reputation as a premier destination for outdoor recreation. Today, tourism is the primary driver of the local economy, with a focus on outdoor activities, arts, and culture.
Major Highways and Landmarks
U.S. Route 26 and U.S. Route 89 are the primary highways serving Teton County, providing access to major attractions such as Grand Teton National Park and Yellowstone National Park. The county is home to several iconic landmarks, including the Grand Teton itself, which rises to 13,775 feet and is a popular destination for climbers and hikers. The National Elk Refuge, located just outside Jackson, offers visitors the chance to observe large herds of elk in their natural habitat. The Snake River, which flows through the county, is another major landmark, known for its scenic beauty and opportunities for fishing, rafting, and wildlife viewing.
7. Campbell County
County Overview
- County Seat: Gillette
- Area: 4,807 square miles
- Population: 46,000 (2020 Census)
- Area Codes: 307
- Latitude: 44.3232° N
- Longitude: 105.5065° W
Location and History
Campbell County is located in northeastern Wyoming and was established in 1911. The county was named after John Allen Campbell, the first Governor of the Wyoming Territory. Gillette, the county seat, has earned the nickname “Energy Capital of the Nation” due to its vast reserves of coal, oil, and natural gas. The county’s history is closely tied to the development of these energy resources, particularly the Powder River Basin, which contains one of the largest coal deposits in the world. The discovery of these resources in the late 20th century led to rapid population growth and economic development, transforming Gillette into a modern, thriving city.
Major Highways and Landmarks
Interstate 90 and U.S. Route 14/16 are the primary highways serving Campbell County, providing vital connections to other regions of Wyoming and neighboring states. Major landmarks in the county include the Eagle Butte Coal Mine, which offers tours to visitors interested in learning about coal production. The Durham Ranch, one of the largest bison ranches in the United States, is another notable landmark, offering a glimpse into the region’s ranching heritage. Additionally, the Wright Centennial Museum provides insights into the history and culture of Campbell County, with exhibits on coal mining, ranching, and Native American history.
8. Lincoln County
County Overview
- County Seat: Kemmerer
- Area: 4,076 square miles
- Population: 19,581 (2020 Census)
- Area Codes: 307
- Latitude: 42.3500° N
- Longitude: 110.5450° W
Location and History
Lincoln County, located in western Wyoming, was established in 1911 and named after President Abraham Lincoln. The county seat, Kemmerer, is known as the birthplace of the first J.C. Penney store, founded by James Cash Penney in 1902. The county’s history is closely tied to the coal and oil industries, with the Kemmerer Coal Mine being one of the oldest continuously operating coal mines in the United States. The region also played a role in the development of the Oregon Trail, with several historic sites marking the path taken by pioneers heading west. Today, the county’s economy is diversified, with a mix of energy production, agriculture, and tourism.
Major Highways and Landmarks
U.S. Route 30 and U.S. Route 89 are the major highways traversing Lincoln County, providing access to both scenic and historical sites. Major landmarks include Fossil Butte National Monument, which preserves some of the richest fossil deposits in the world, offering visitors a glimpse into the region’s prehistoric past. The Star Valley, known for its stunning landscapes and outdoor recreation opportunities, is another key landmark in the county. The historic J.C. Penney store in Kemmerer is a popular tourist attraction, celebrating the legacy of one of America’s most iconic retailers.
9. Laramie County
County Overview
- County Seat: Cheyenne
- Area: 2,688 square miles
- Population: 100,512 (2020 Census)
- Area Codes: 307
- Latitude: 41.3129° N
- Longitude: 104.2454° W
Location and History
Laramie County is located in southeastern Wyoming and is the most populous county in the state. Established in 1867, the county was named after Jacques La Ramee, a French-Canadian fur trader. Cheyenne, the county seat, is also the state capital and has a rich history tied to the development of the Union Pacific Railroad. The arrival of the railroad in the late 19th century transformed Cheyenne into a bustling frontier town, attracting settlers, ranchers, and businesses. The county’s history is also marked by its role as a center for livestock production, particularly cattle and sheep, which continue to be important to the local economy. Today, Laramie County’s economy is driven by government, military, and transportation sectors.
Major Highways and Landmarks
Interstate 80 and Interstate 25 intersect in Laramie County, making it a key transportation hub in Wyoming. U.S. Route 85 and U.S. Route 30 also pass through the county, providing additional access to various destinations. Major landmarks in Laramie County include the Wyoming State Capitol, a historic building that serves as the seat of government for the state of Wyoming. The Cheyenne Depot Museum, housed in the historic Union Pacific Railroad Depot, offers exhibits on the county’s railroad history. Additionally, Frontier Days, the largest outdoor rodeo and western celebration in the United States, is held annually in Cheyenne, attracting visitors from across the country.
10. Converse County
County Overview
- County Seat: Douglas
- Area: 4,255 square miles
- Population: 13,751 (2020 Census)
- Area Codes: 307
- Latitude: 42.7567° N
- Longitude: 105.3825° W
Location and History
Converse County, located in eastern Wyoming, was established in 1888 and named after A.R. Converse, a pioneer and cattleman. The county seat, Douglas, is known for its rich history and connection to the Wyoming State Fair, which has been held annually since 1905. The county’s history is deeply tied to the livestock industry, with cattle and sheep ranching playing a central role in its development. The discovery of oil and natural gas in the early 20th century added another dimension to the local economy, leading to periods of economic growth and population expansion. Today, Converse County’s economy is driven by a mix of energy production, agriculture, and tourism.
Major Highways and Landmarks
Interstate 25 and U.S. Route 20/26 are the major highways running through Converse County, connecting it to other parts of Wyoming and the region. Major landmarks include the Ayres Natural Bridge, a stunning natural rock formation that spans LaPrele Creek and is one of the few natural bridges in the country with water flowing beneath it. The Fort Fetterman State Historic Site, located just outside of Douglas, offers a glimpse into the military history of the region, with preserved buildings and exhibits on the Indian Wars of the late 19th century. The Wyoming Pioneer Memorial Museum, also located in Douglas, celebrates the history of the county’s early settlers and the development of the livestock industry.
List of All Counties in Wyoming Alphabetically
Below please see all Wyoming counties which are listed in alphabetical order.
- Albany County, WY
- Big Horn County, WY
- Campbell County, WY
- Carbon County, WY
- Converse County, WY
- Crook County, WY
- Fremont County, WY
- Goshen County, WY
- Hot Springs County, WY
- Johnson County, WY
- Laramie County, WY
- Lincoln County, WY
- Natrona County, WY
- Niobrara County, WY
- Park County, WY
- Platte County, WY
- Sheridan County, WY
- Sublette County, WY
- Sweetwater County, WY
- Teton County, WY
- Uinta County, WY
- Washakie County, WY
- Weston County, WY
Map of Wyoming Counties
