She may be young, but King is an experienced rider.
"I love riding horses, it's one of my favorite things to do," she says.
This 15-year-old equestrian is joining other enthusiasts on a re-ride of the Pony Express.
"I like carrying on the history that most people don't remember. A lot of the history is forgotten, so it makes me feel good to reenact history," King said.
"They will for the next 10 days be travelling 24 hours a day, 200 miles per day, to California," explains Gary Chilcote, president of the Missouri chapter of the Pony Express Association.
The re-ride will conclude in Sacramento, but King won't be going that far.
She's just going to Elwood, KS, where other riders will take the mochila from her horse and continue the trail.
The Pony Express Association tries to be as authentic as possible with the route they take and the methods they use.
"We try to tell the story of what occurred here so that people remember it for future generations," Chilcote said.
And after swearing the Pony Express Riders' Oath, the riders set off to carry with them 151 years of St. Joseph's history.
This is the 32nd re-ride of the Pony Express.
This year's ride will use 550 riders from Missouri to California.