Wyomings Fort Caspar (Casper) was originally known as Platte Bridge Station. It was built in the Oregon Trail's later years, primarily to protect the telegraph office. As hostility with the tribes in the region increased, the fort expanded and about 100 soldiers were eventually garrisoned there.

In July of 1865, Fort Caspar was the site of a major attack. A military wagon train was heading towards the fort from the west when suddenly thousands of Sioux, Cheyenne and Arapaho attacked. Only three of the 25 soldiers in the wagon train survived.

In a separate battle on the same day, four more soldiers were killed, including Lt. Caspar Collins. He was killed in the conflict while attempting to escort an Army supply train to the post. The Army officially changed the name from Platte Bridge Station to Fort Caspar in memory of the fallen lieutenant. The tribes considered these raids to be retaliation for a brutal massacre a few months earlier in Sand Creek, Colorado.

Today, experience the mystique of this historic Wyoming place by visiting the collection of reconstructed fort buildings at the original location of Platte Bridge Station and Louis Guinard's Platte Bridge (1859-60 construction). The Museum features cultural and natural history exhibits of Central Wyoming including the living history festivals and lectures offered during the summer months. The Fort Caspar buildings are open May through September and the Museum is open year round.