Casper is in east central Wyoming, on the North Platte River.

Casper was established east of the former site of Fort Caspar, in an area that attracted European settlers during the mid-19th century mass migration of land seekers along the Oregon, California, and Mormon trails,[8] where several nearby ferries offered passage across the North Platte River in the early 1840s.

In 1859, Louis Guinard built a bridge and trading post near the original ferry locations, allowing overland travel to continue through the area.

[9] The government also posted the military garrison to protect telegraph and mail service.

[8] Native American attacks increased after the 1864 Sand Creek Massacre in Colorado, bringing more troops to the post, which was by now called Platte Bridge Station.

But the town itself was settled in 1887, and incorporated a year later by developers as an anticipated stopping point during the Wyoming Central Railway's expansion.

Casper was an early commercial rival to both Bessemer and Douglas, Wyoming.

Casper received a significant influx of visitors during the solar eclipse of August 21, 2017, due to its position along the path of totality.

[14] Interstate 25, which approaches Casper from the north and east, is the main avenue of transportation to and from the city.

The towns immediately adjacent to Casper are Mills, Evansville, and Bar Nunn.

Unincorporated areas include Allendale, Dempsey Acres, Red Buttes, and Indian Springs.

[15] Like most of Wyoming, Casper has a continental semi-arid climate (Köppen climate classification: BSk), with long, cold, dry winters, hot but generally dry summers, mild springs, and short, crisp autumns.

Precipitation is greatest in spring and early summer, but even then is not high.

Development of Wyoming coal and uranium fields in recent decades has helped Casper continue its role as a center in the energy industry.

This logistics firm transports overweight and outsized components used in the wind power industry.

[50] In the summer, Casper's City Band performs free concerts Thursday evenings at Washington Park.

[48] Wyoming National Bank, a mid-century modern tower, was designed by Charles Deaton and is featured in Casper's logo.

[51] Interstate Highways: US Routes: Wyoming State Highways: The city has scheduled air service at Casper–Natrona County International Airport, a former army air base built during World War II.

It replaced Wardwell Field north of Casper, which later became the town of Bar Nunn.