Natrona County, Wyoming

Natrona County lies at the intersection of the basins, mountains and great plains of Wyoming that remain after billions of years of geological change. Here, water and wind have exposed rock layers, creating a dramatic landscape. Red outcroppings of sandstone vie with white limestone and variegated granites. Distinctive land features include Casper Mountain, Independence Rock, the Red Buttes, Devil’s Gate and Teapot Rock.

Much of the county holds buried treasures of oil and natural gas. More visible are outcrops of coal, remains of primordial swamps. Early-day prospectors also exploited deposits of copper, trona and asbestos.

This is an arid environment averaging ten inches of moisture per year, but few years are average. The mountains, such as Casper Mountain, receive considerably more moisture, usually in late winter snow storms. Run-off in the early summer can lead to flooding of the North Platte and Sweetwater rivers as well as smaller tributaries. Only man-made reservoirs prevent wholesale damage downstream.

Sheep outnumbered cattle in Natrona County by 1903, when this band of  3,000 crossed the North Platte River near Alcova. Stimson Collection,  Wyoming State Archives.Ancient nomads traveled through and lived in the area that would later become the county between 12,000 and 9,000 years ago. These people traveled during the warmer seasons and then settled in sheltered areas for the winter. They hunted big game like bison antiquus aaaaaand columbian and woolly mammoths, as well as smaller animals, and gathered edible plant materials such as berries and seeds.

Archaeologists have excavated a number of areas in Natrona County, mostly bison kill and butchering sites. A dig conducted in 2006 by local archeo-geologist John Albanese at Hell’s Half Acre, west of Casper, Wyo. found spear points and other materials that dated from 3,000 to 1,200 years ago. In 1971, Wyoming State Archaeologist George Frison excavated a bison kill site west of Casper, on the north bank of the North Platte River. The site dated from 10,000 to 9,500 years ago.

More recent Indian groups, including the Lakota, Northern Cheyenne, Arapaho, Crow and Shoshone tribes migrated through and occasionally wintered in the county, beginning in the 1700s. Their lives came under increasing pressure after the arrival of Euro Americans. By the late 1800s, the U.S. government required most tribes to settle on reservations. Even so, bands of Lakota and Shoshone traveled through the county into the 1890s.

Many early European explorers came through Wyoming, among them Robert Stuart and his companions, who traveled east from Fort Astoria on the Pacific coast in 1812. History credits Stuart with recording the first European travel west to east on what became known as the Oregon Trail. A later explorer and mapmaker, John C. Frémont, nicknamed ”The Pathfinder,” gave the North Platte’s modern-day Pathfinder Dam and Reservoir their name. Photographer William Henry Jackson, who traveled with mapmaker Ferdinand Hayden, documented his travels through present‑day Natrona County in photographs and paintings.

In the mid-19th century, the North Platte and Sweetwater rivers became the route for numerous travelers moving to Oregon, California or the valley of the Great Salt Lake. The Oregon/California/Mormon Trail followed the river upstream from Nebraska, allowing emigrants to follow a clear path west.

Dangerous river crossings prompted entrepreneurs to construct ferries and bridges from what is now Douglas, Wyoming west into the Sweetwater country. The Archambault brothers and Charles Lajeunesse ran the Sweetwater bridges in the 1850s. First the Mormons ran a ferry just west of Casper, near present-day Mills, and then Louis Guinard established a bridge nearby. John Richard operated a series of bridges, the most notable being the one at what’s now Evansville,Wyo., east of Casper.

Beginning in the 1850s, the U.S. Army posted troops along the river to protect travelers at the crossings and later to defend the new telegraph line connecting the eastern states and California. In 1865, two famous battles between Indians and soldiers occurred in what is now Natrona County near an army post built at Guinard’s bridge. During the Battle of Platte Bridge Station on July 25, 1865, Cheyenne and Lakota warriors killed numerous soldiers including Lieutenant Caspar Collins. On the same day, more Indians attacked Sergeant Amos Custard and his small supply train a few miles to the west. In honor of Collins, the Army designated the post as Fort Casper, misspelling his name in the process. In 1888, the town of Casper, soon to be the county seat of Natrona County, also took Collins’s misspelled name.

Some of the earliest businesses in the county were cattle and sheep operations. Joseph Carey and his brother controlled much of the west side of the county including parts of what later became Casper. Joseph Carey later became a U.S. senator and Wyoming governor. Bryant B. Brooks, another land baron who invested in cattle and sheep, was also elected Wyoming governor. Texas rancher Gilbert Searight established the Goose Egg Ranch near Bessemer, west of Casper. The Goose Egg ranch house was a hotel, restaurant and possibly used as the setting for part of Owen Wister’s novel, The Virginian. Searight sold out to the Carey Brothers in time to avoid the horrible winter of 1886-1887.

Out in the Sweetwater country the biggest ranchers were Tom Sun, Bonaparte “Boney” Earnest, Albert and John Bothwell, and Tom and John Durbin. Perhaps the most notorious incident in that part of the county was the hanging of James Averell and Ellen Watson on July 20, 1889, by vigilantes Tom Sun, John Durbin, Albert Bothwell, Robert Conner, Robert Galbraith and Ernest McLean. A grand jury failed to bring charges against the men. Publicity, almost certainly engineered by the vigilantes, branded Watson as Cattle Kate, a notorious rustler, tarring her reputation until new research turned up the real story, clearing her name, in the 1990s.

In addition to the owners of large parcels of land were numerous smaller ranchers; some raised cattle and somer raised sheep. Sheep began appearing on the ranges mostly in the northern and western parts of the county in the 1880s, but sheep ranching was not a big part of the economy until the 1890s. Many of the sheepmen were Irish immigrants and some of them, too, eventually controlled large acreages of land.

But as sheep numbers rose in the 1890s, and numbers of cattle gradually declined, tensions between cattlemen and sheep ranchers led to violence over who would get to use the open range. Particularly in northern Wyoming, some cattlemen tried to eliminate their competition, killing entire bands of sheep and sometimes sheepherders. In 1909, the peak year for sheep, there were around 6 million in Wyoming, and only about a seventh as many cattle. Cattle-sheep ratios were probably similar in Natrona County. In the early 1910s, tensions between cattle and sheep raisers finally began to decrease.

As towns sprang up in the late 1880s, residents began seeking a county government with the infant town of Casper at the center of this effort. In 1890, Territorial Governor Francis E. Warren signed legislation splitting Carbon County in two with the north half becoming Natrona County. Casper and Bessemer, ten miles farther up the North Platte, vied for the plum title of county seat. Bessemer got more votes, but the number was so much larger than the hamlet’s actual population that election officials declared the returns fraudulent, and Casper won the election, ensuring its survival and leading to Bessemer’s demise.

Casper in 1890 was hardly an upscale community. Most buildings were wood, but the addition of new government buildings constructed of sturdy brick led to reconstruction and expansion of business blocks in brick and stone. The Fremont, Elkhorn and Missouri Valley Railroad and later the Burlington Northern made the town into a supply and distribution hub. Other towns began to grow as ranching and oil discoveries drew people to the far reaches of the county.

Along with government and business infrastructure, houses, schools and churches made the towns good places to live and raise families. Newspapers competed aggressively for readers while detailing all of the comings and goings of residents and businessmen. Alfred Mokler, who arrived in 1897 to run the Natrona County Tribune, became an influential local opinion-maker. When he wrote his opinionated, but mostly factual History of Natrona County, Wyoming, 1888-1922 in 1923, he also became the official chronicler of the county’s past.

Little did people realize the immense changes that were coming their way when Cyrus Iba filed for the first oil lease in the county in the early 1880s. Beginning in the 1890s, scores of investors began to converge on Casper and by the turn of the century, test wells were common in the area. Mark Shannon created the Pennsylvania Oil and Gas Company in 1888 to exploit possible oil properties in the Wyoming fields.

Transportation problems and the need for a local refinery hampered early efforts, but soon Pennsylvania Oil and Gas built a refinery in Casper. French and Belgian investors also set up operations, but it was the Midwest Oil Company in 1910 that began the first really big development. John D. Rockefeller’s Standard Oil was a latecomer. By the end of the 1920s, he had bought out most of the competition.

Around the same time, federal funds first came to the county in a substantial way with the construction of Pathfinder Dam on the North Platte River in Fremont Canyon, near the southern border of Natrona County. The U.S. Reclamation Service built the dam to store water for irriagation. Freight and supplies were shipped 50 miles out from Casper by mule train. The dam was completed in 1911.

The Midwest Oil Company Refinery in Casper, shown here around 1920 with  the North Platte River in the foreground, was later bought by Standard  Oil. Blackmore Collection, Casper College Western History Center.

In the 1910s and 1920s, the Salt Creek oil patch at the northern end of Natrona County was the largest production field in the world. This drew thousands of workers and their families, most of the men veterans of World War I, to Casper and the small towns that cropped up in the oil district. Salt Creek (later renamed Midwest), Edgerton, Lavoye and Snyder were just a few of the towns that arose almost over night. Edgerton and Midwest were the only towns to survive.

The Great Depression arrived in most of the nation after the stock-market crash of 1929. But economic difficulties hit Wyoming’s oil industry years earlier, in 1926. As prices and demand dropped, Natrona County experienced its first energy bust, and many people left.

After President Franklin Roosevelt took office in 1933, New Deal programs brought much- needed money and jobs into the county. Civilian Conservation Corps workers helped build roads and ski slopes on Casper Mountain. Works Project Administration and Public Works Administration money contributed to the construction of a replica of Fort Casper on its original site, a new post office and federal building downtown and provided funds for Alcova Dam, a U.S. Bureau of Reclamation project 30 miles upstream on the North Platte.

World War II, which began for the United States on December 7, 1941, finally brought the country out of the Depression and took hundreds of thousands of young men and women off to war. The war also brought the Casper Army Air Base to what is now the Natrona County International Airport. The base provided jobs for locals and introduced flyers-in-training to Wyoming hospitality.

After the war, many veterans returned to the state. They started families, found jobs and readjusted to their postwar lives. Natrona County’s population grew by more than 30 percent, from 23,858 to 31,437, between 1940 and 1950. In the following decade, population increased another 57 percent, reaching 49,623.

Key Dates

April 12, 1890

Natrona County organized with Casper as its county seat.

Date: 1890-04-12

April 8, 1890

Election for county seat of Natrona County brings in 296 votes for Casper and 697 votes for Bessemer. Bessemer may have had as few as two dozen residents at the time, however. Organizing commissioners ruled the Bessemer vote fraudulent and awarded county seat status to Casper.

Date: 1890-04-08

Natrona County, looking north  from Casper Mountain. Tom Rea photo.

Natrona County
quick facts

Land Area

5,558 square miles, 5th largest in Wyoming

Land Ownership
in Natrona County

Owner Acres Percent
US Government    
Forest Service 5,568 0.16
Fish & Wlidlife 7,552 0.21
Bureau of Land Management 1,442,016 39.98
Bureau of Reclamation 7,424 0.21
State Lands Comm. 396,418 11.14
State Recreation Comm. 516 0.01
Game & Fish 147 0.00
Local Government/Other    
Total Public Lands 1,864,387 52.41
Private Lands 1,692,733 47.59
Surface Water 22,931 0.64
Total Area 3,191,814 100

Natrona County Population

75,450 (2010 U.S. Census)

Incorporated Towns

Town Population
Casper (county seat) 55,316
Bar Nunn 2,213
Evansville 2,544
Mills 3,461
Edgerton 195
Midwest 404

Unincorporated Communities

Powder River  

Employment by sector
(2008 state figures)

Sector Population
Agriculture 490
Mining 5,610
Construction 4,484
Retail 6,632
Transport/Warehouse ND
Health care/Social assistance 6,206
Food & Lodging 3,973
Finance/Insurance/Real Estate 5,140
Federal, state, local gov't 6,151
Other sectors 17,236
Total 55,922

ND=not disclosed to avoid disclosure of confidential information, but estimates included in totals.

Sources: Wyoming Division of Economic Analysis Equality State Almanac, County Profiles, ; Wyoming DEA summary of decennial U. S. Census data,; Wyoming DEA Employment, Income, and Gross Domestic Product Report,

About the Author

Rebecca A. Hunt, Ph. D. is a historian teaching at the University of Colorado Denver, where she specializes in social history of the American West and public history. She writes on community, gender and ethnic history. Dr. Hunt was the historian on the award-winning documentary about Neal Forsling of Casper Mountain, A Woman to Match a Mountain (2008). Wyoming Medical Center, A Centennial History was published in January 2011. Her most recent book, Natrona County: People, Place and Time, published in October 2011 is available at the Fort Caspar Museum. She is working on a history of Forsling, a Casper woman homesteader, painter and author.

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