Platte County, Wyoming

Platte County, in southeastern Wyoming, lies along the east slope of the Laramie Range, part of the front range of the Rocky Mountains. The county is a rectangle, 65 miles long north to south and 30 miles wide, with the North Platte River running through its northeastern corner.

Most of the county is dominated by the blue cone of Laramie Peak on its western horizon, and a north-south travel route along the mountain front, used by people since prehistoric times, dominates its economy as today’s Interstate 25. Water has been diverted from the river and its tributaries since the 1880s, and remains important to Platte County agriculture and to a large, coal-fired power plant today.


Tribes and trappers

Among Platte County’s early residents were the Shoshone and a tribe that Lewis and Clark called the Saitan, forerunners of the Cheyenne. In the early 1700s, the Comanche took over the area, joined by the Arapaho around 1795 and the Cheyenne a few years later. The Crow entered the area around 1800. The Platte River tribes—Lakota Sioux, Cheyenne and Arapaho--eventually edged the Shoshone west of the continental divide and the Crow to the north, and controlled areas along the river.

During the fur trade era, from the early 1820s through about 1840, trappers and traders made their way west along the North Platte River en route to the annual rendezvous trade fairs on the upper Green River. The American Fur Company built Fort William, later renamed Fort Laramie, in what is now Goshen County, Wyo., and in the mid-1830s, missionaries began joining fur company employees on the journey to the mountains.

In the 1840s, with little regard to Indian claims to the land, white settlers began traveling through the region on what later became the Oregon, Mormon and California trails, all more or less a single route at this point along the North Platte River. After the California gold rush began in 1849, the trails were used much more heavily.

Transport and ranching

In 1867, the Union Pacific Railroad reached Cheyenne and the U.S. Army opened a supply depot at Fort D.A. Russell nearby. A freight road was opened from there to Fort Laramie. A telegraph line paralleled the road as well, and along the way roadhouses and stage stops sprang up, many in the future Platte County.

Through the mid-1800s, the region that would become Wyoming provided open range for profitable sheep and cattle ranching. The Swan Land and Cattle Company, founded by brothers Alexander and Thomas Swan in the 1870s and headquartered in Chugwater, grew into a vast operation. At its peak, the brothers claimed to own 100,000 head of cattle that ranged from Ogallala, Neb., to Rawlins, Wyo., a stomping ground of several million acres.

After gold was discovered in the mid-1870s in the Black Hills of Dakota Territory, the Cheyenne-Fort Laramie freight road was extended north to the gold camps. The entire route became known as the Cheyenne-Deadwood Stage Road, running through eastern Wyoming Territory and parts of the future Platte County. It became busy with freight and passenger traffic, famous for its use by such colorful travelers as Wild Bill Hickok, Calamity Jane, Buffalo Bill and Wyatt Earp, and notorious for the outlaws and road agents who preyed on the gold shipments.

wheatland3.jpgHartville, Sunrise and Guernsey

Late in the 1870s, prospectors from Fort Laramie found copper about 15 miles away, in the hills north of the North Platte River in what’s now northeastern Platte County. In 1884, the miners’ camp was incorporated and named Hartville, for Col. Verling K. Hart, an officer from Fort Laramie and owner of one of the earliest mining claims.

Just east of Hartville, copper deposits were discovered and the Sunrise Mine was established around the same time—and named for the good view the spot offered out to the east and the rising sun.

By the late 1880s the copper prospects were dwindling, and miners turned to iron ore, which would prove far more lucrative. In 1898, the Colorado Fuel and Iron Company, part of the widespread iron and steel interests of John D. Rockefeller, acquired the Sunrise Mine as an iron-ore prospect, and began building a company town there in 1899.

wheatland4.jpgThe company owned everything in the town—the store, the miners’ four-room houses, a boarding house and a social hall. Nearby Hartville was not owned by the company and remained a rougher place, as it offered saloons to the people of Sunrise. Miners and their families from Greece, Italy, England, Japan, Lebanon, the Scandinavian countries and many more settled in Hartville and Sunrise. Some started businesses in Hartville and stayed to become established members of the communities.

At its peak of operations, the Sunrise Mine employed 700 workers and extracted thousands of tons of ore per year. The mine closed in 1980, and the town was abandoned. Many foundations and some of the buildings remain.

In 1900, meanwhile, the Burlington Railroad, building west up the North Platte River from Nebraska, entered Wyoming. In 1902, the railroad’s land company established the town of Guernsey, on the river five miles south of Hartville, near a pair of famous landmarks on the old Oregon Trail—Register Cliff and the Oregon Trail Ruts. Guernsey quickly prospered as a shipping point, where the rail spur to the mines joined the Burlington line.

Platte County named for the river

Growing populations in Wheatland and the Guernsey-Hartville-Sunrise area led the Legislature to create a new county out of the northwestern parts of Laramie County in 1911. Gov. Joseph M. Carey signed the bill establishing the county on Feb. 9, 1911. Organizing commissioners Chris Hauf of Glendo, T.J. Carrol of Wheatland and Robert Grand Jr. of Chugwater first met on March 8, local voters approved the idea in November 1912 and the county government was finally organized on Jan. 7, 1913.

Platte County is bordered on the northeast by Niobrara County; on the east by Goshen County; on the south by Laramie County; on the west by Albany County; and on the northwest by Converse County. Platte County includes five towns: Chugwater, Glendo, Guernsey, Hartville and Wheatland. Smaller, census-designated places are Chugcreek, Lakeview North, Slater, Westview Circle, Y-O Ranch, Whiting and Sunrise.

The county was named for the North Platte River. In the 1790s, French fur traders and trappers named the river “Platte,” from the French for “flat” or “shallow.” The river to this day is the lifeblood of the area, providing water to more than 335,000 acres in Wyoming and Nebraska, enabling the semi-arid plains to produce alfalfa, corn, potatoes, sugar beets and dry beans.

Irrigation and dams

Local lore credits Cheyenne-based politician and Judge Joseph M. Carey, later Wyoming’s U.S. senator and governor, businessman Andrew Gilchrist and poet Johnny Gordon with turning cactus-covered prairie into a valuable irrigation district. In 1878, Carey and Gordon brainstormed about an irrigation project to divert water from the Laramie River to Blue Grass and Sybille creeks and onto the Wheatland Flats and planned canals to take water to specific farmlands.

Wheatland Flats, around present-day Wheatland, Wyo., covers about 20 miles between the Laramie Mountains on the west and Chugwater Creek on the east and extends about 22 miles from the Laramie River on north to the Richeau Hills to south.

wheatland5.jpgCarey organized a committee for the project and finalized plans in the winter of 1882. Work began a few months later. In 1883, the Wyoming Development Company was formed to oversee construction and officials of the company also allocated water rights. Other investors included Francis E. Warren, later governor and U.S. senator, and ranchers William Irvine and Horace Plunkett. In 1884, farmers began settling on lands in this irrigation district. The Cheyenne and Northern Railway, building north from Cheyenne, reached the Wheatland Flats area in 1887. By 1897, water stored in reservoirs in north-central Albany County and then piped to the Flats provided added irrigation.

The development caused an upsurge of settlement. Lots were sold in the new town of Wheatland in 1894, and it was finally incorporated in 1905. When Platte County was formed in 1911, Wheatland was chosen as county seat. As Wyoming water law continued to evolve, the Wyoming Development Company eventually became the Wheatland Irrigation District, a public board still administering irrigation projects in Platte County.

As Platte County moved into the 20th century, the need for more irrigation water led to construction of two important dams on the North Platte River at the northern end of the county.

In 1902, President Theodore Roosevelt signed the Reclamation Act to fund irrigation on federal lands in the American West. Pathfinder Dam, on the North Platte 100 miles upstream from Platte County, was completed in 1909.

That same year, the U.S. Senate Committee on Irrigation and Reclamation came to Wyoming on a fact-finding mission. State Sen. Charles Guernsey, for whom the town of Guernsey was named, advocated for a site on the North Platte River for its capacity for water storage and its potential for production of electric power. He successfully persuaded committee members to look at his Guernsey site. Their enthusiasm eventually led to congressional authorization for the project, which became known as the Guernsey Dam.

Key Dates

Jan. 7, 1913

Platte County organized.

Date: 1913-01-07

Platte County
quick facts

Land Area

2,085 square miles, 21st largest in Wyoming

Land Ownership
in Platte County

Owner Acres Percent
US Government    
Forest Service 1,151 .09
Bureau of Land Mgmt. 82,560 6.11
Bureau of Reclamation 10,688 .70
State Lands Comm. 157,441 11.65
Recreation Comm. 320 .02
Game & Fish 40 .00
Local Government/Other 60,271 4.46
Total Public Lands 312,471 9.14
Private Lands 1,038,505 76.87
Surface Water 16,621 1.23
Total Area 1,350,976 100

Platte County Population

8.667 (2010 U.S. Census)
8,796 (2011 State Estimate)

City, Town and
Census-designated Places

Town Population
Wheatland (county seat) 3,627
Chugwater 212
Glendo 205
Guernsey 1,147
Hartville 62
Chugcreek (CDP) 156
Lakeview North (CDP) 84
Slater (CDP) 80
Westview Circle (CDP) 52
Whiting (CDP) 83
Y-O Ranch 195

Employment by sector
(2009 state figures)

Sector Population
Farm 582
Forestry, Fishing & Related (D)
Mining (D)
Construction 367
Utilities (D)
Manufacturing 113
Wholesale Trade (D)
Retail Trade 553
Transportation & Warehousing 295
Information 33
Educational (Services) (D)
Health Care & Social Assistance (D)
Arts/Entertainment/Recreation 74
Accommodations & Food Service 362
Management of Companies 28
Finance & Insurance 263
Real Estate, Rentals & Leasing 312
Professional, Scientific & Technical 194
Administration & Waste Services 130
Other Services except Public Admin. 252
Fed, state, local gov't 972
Total 7,604

D=not disclosed to avoid disclosure of confidential information, but estimates included in totals.
L=less than 10 jobs, 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,; 2010 Census Summary Report for Wyoming,
; 2011 county population estimates,

About the Author

Nicole Lebsack grew up in Newcastle and attended the University of Wyoming. She recently graduated from the University of Missouri-Columbia with a master’s degree in journalism with an emphasis in news editing/design and works at the Wyoming TribuneEagle. Her articles and page designs have appeared in the News Letter Journal and Columbia Missourian newspapers.

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