Just in time for Halloween, here's another spooky story about one of Wyoming's many historic haunts.

The Fort Laramie National Historic Site dates all the way back to 1834, when it was originally established as a frontier trading post called Fort William. A popular resting stop for wagon trains headed west, it was replaced by Fort John in 1841. In 1849, the Fort Laramie military post was built to protect early settlers from conflicts with local Native American tribes.

Over the years, there have been many ghost sightings across the property, none more famous than the "Lady in Green". Legend has it, she was the daughter of an American Fur Company agent at the old Fort John.

After mysteriously vanishing from the camp, her ghost is said to appear every seven years, wearing a long, green dress and riding a black stallion along the Oregon Trail just east of the fort.

In 1870, a building was added to the site to house the commanding officers. According to several former soldiers and staff members, the old Captain's Quarters are often visited by the spirit of a man they call "George".

Another building on the site, known as Old Bedlam, is reportedly haunted by the ghost of a cavalry officer known to walk around the structure urging visitors to "be quiet". Then there is the Cavalry Barracks, which is said to house the spirits of hundreds of former soldiers who once lived there.

Other reported apparitions around the fort include a young man in a raincoat, a doctor in a blood-soaked uniform, an angry Civil War soldier, a man brandishing a sword covered in blood and even a headless man who has been spotted throwing rocks into Deer Creek in the wee hours of the morning.

See the photos of the historic site.