north platte river

Built in 1834 at the Laramie-Platte confluence, Fort William was Wyoming’s first permanent trading post, precursor to Fort John and Fort Laramie. Champagne christened its name after a dispute among its builders. Its exact location remains unknown despite decades of archaeological searching.

In 1837, Pierre Sarpy built a seasonal outpost near Fort William on the North Platte to feed the fur trade’s booming robe market. Abandoned within a year, its exact location was never recorded, and Fort Sarpy remains one of Wyoming’s most obscure trading posts.

In the cold winter of 1831-32, 21 fur trappers survived—in fact thrived—on the Laramie Plains, but it was another matter for their horses. One of the men was 22-year-old Zenas Leonard. He had left the family farm in Pennsylvania after announcing “I can make my living without picking stones.” 

Westbound wagon-train emigrants got their first glimpse of the Rocky Mountains when they first saw the blue cone of Laramie Peak, 85 miles away. Snowcapped in early summer, the mountain stayed in sight for a week or more, dominating many diarists’ accounts and foreshadowing drier, more difficult country ahead.

The basin of the North Platte River takes up the southeastern quarter of Wyoming, plus a finger of land along the tributary Sweetwater River in the center of the state. The courses of the North Platte and Sweetwater determined early fur-trade and emigrant routes. Since that time, the basin’s water and other resources have continued to draw industry, stock raising, dams and irrigation—and people.

Saratoga, famed for its hot springs, has often been called the place “where the trout leap in Main Street.” Treasured by fishermen, hunters and outdoor lovers, the town continues to thrive on the tourist trade. A sawmill, mainstay of the local economy from 1934 to 1983, recently re-opened. 

When completed in June 1909 on the North Platte River, 47 miles southwest of Casper, the granite Pathfinder Dam was a triumph of early 20th century design. It was one of the earliest federal Reclamation Service dams in the West, and convinced agency officials of their ability “to do great things.”

Seminoe and Kortes dams, both located in a remote stretch of northern Carbon County, Wyo., were constructed in the 1930s and 1940s primarily for the production of hydropower. While power plants at both dams still generate electricity, the area is frequented by tourists, especially fishermen who travel to the renowned Miracle Mile, just downstream from Kortes Dam, to catch trout.

In 1869, Fort Fred Steele was built by the U.S. Army to protect workers on the advancing transcontinental railroad at the spot where the rails crossed the North Platte River. The fort was closed in 1886, and the site, containing foundations of the original buildings, was much later acquired by the state.

Though the site was an important river crossing on the early frontier, the town of Casper did not begin until 1888, when the Fremont, Elkhorn & Missouri Valley Railroad reached the area. The town immediately became an important shipping point for cattle and wool. The first oil refinery was built in 1895 to process crude oil from the Salt Creek Oil Field, 40 miles to the north. The first true oil boom began after 1910 and lasted through the mid 1920s, and the town’s fortunes have been closely connected to the energy business ever since. In 2010 the city’s population passed 55,000. Casper continues as a retail, medical and energy-industry service hub.