The book, "The South Dakota Road Guide to Haunted Locations", has been flying off bookshelves since last summer.
The authors re- visited Rapid City to sign books, and hear about any new spooky sites, they may have missed.
Co-author Terry Fisk is actually from Wisconsin, but has researched ghost stories all across the midwest for he and co-author Chad Lewis' haunted road guides.
They've done them for Wisconsin, Minnesota, South Dakota, Iowa, and are just about done with one for Illinois.
Inspired by an unusual picture he had taken in a cemetery, Fisk has researched haunted places ever since.
In the book, Fisk and Lewis write about three "haunted" places in Rapid City.
They also write about a couple dozen other locations across the state. He says South Dakota was different from the other states they've researched because of the sparse population, but the scary stories were never hard to find.
"It's rare that we have people say they don't know anyplace a lot of times we'll come into a town and they'll say the entire town is haunted, our school, casino, local store is haunted, they have all these haunted houses right in neighborhood." says Fisk.
Fisk says their books appeal to adventure seekers who want to find out where the best hauntings are and for those who would rather read about the haunted places in the safety of their homes.