(COLORADO) — A new study has ranked the best ghost tours in the nation, and a Denver-area tour is the only Colorado attraction to make the list. Online casino site Jeffbet analyzed Tripadvisor reviews to find the highest-rated ghost tours in America. An index was created based on each attraction’s average rating on Tripadvisor, the percentage of 5-star ratings, and total number of Tripadvisor reviews. The tours were then ranked from highest to lowest based on those statistics. History and Hauntings of Salem Guided Walking Tour in Massachusetts was awarded the top spot in the study, with an index score of 97.25 out of 100. It has an average rating of 4.91 out of 5 from 6,636 Tripadvisor reviews and 94.88% of reviewers rating it 5 stars. Led by a local historian, this walk takes you through the haunted history of Salem, Massachusetts and can be booked for the evening if you are looking for a spookier tour.  Colorado ranked 19th on the list, with Twilight Ghost Tours of Denver. The tour takes guests through a historic district, and features haunted locations including the Molly Brown House and the Peabody-Whitehead Mansion, which was featured on a 2012 episode of Travel Channel's hit ghost hunting series Ghost Adventures. Molly Brown House. Courtesy: KDVRThis March 2, 2012 photo shows Janet Kalstrom, a retired banking project manager who been the museum's Molly Brown impersonator for six years in the living room at the Molly Brown House Museum. A few blocks from Colorado's state Capitol _ over 1700 miles from the Atlantic Ocean and a mile above sea level _ is a museum dedicated to a woman eclipsed by legend following the sinking of the Titantic. The "unsinkable Molly Brown" moved into this stone Victorian home after she and her husband struck it rich at a gold mine in Colorado's mountains, nearly 20 years before she boarded the Titanic because it was the first boat she could get back home to visit her ailing grandson. (AP Photo/Ed Andrieski)This March 12, 2012 photo shows the front of the Molly Brown House Museum in Denver. A few blocks from Colorado's state Capitol _ over 1700 miles from the Atlantic Ocean and a mile above sea level _ is a museum dedicated to a woman eclipsed by legend following the sinking of the Titantic. The "unsinkable Molly Brown" moved into this stone Victorian home after she and her husband struck it rich at a gold mine in Colorado's mountains, nearly 20 years before she boarded the Titanic because it was the first boat she could get back home on to visit her ailing grandson. (AP Photo/Ed Andrieski)This March 12, 2012 photo shows lions guarding the front of the Molly Brown House Museum in Denver. A few blocks from Colorado's state Capitol _ over 1700 miles from the Atlantic Ocean and a mile above sea level _ is a museum dedicated to a woman eclipsed by legend following the sinking of the Titantic. The "unsinkable Molly Brown" moved into this stone Victorian home after she and her husband struck it rich at a gold mine in Colorado's mountains, nearly 20 years before she boarded the Titanic because it was the first boat she could get back home to visit her ailing grandson. (AP Photo/Ed Andrieski)This March 19, 2012 photo shows a banner on display in the Molly Brown House Museum in Denver. A few blocks from Colorado's state Capitol _ over 1700 miles from the Atlantic Ocean and a mile above sea level _ is a museum dedicated to a woman eclipsed by legend following the sinking of the Titantic. The "unsinkable Molly Brown" moved into this stone Victorian home after she and her husband struck it rich at a gold mine in Colorado's mountains, nearly 20 years before she boarded the Titanic because it was the first boat she could get back home to visit her ailing grandson. (AP Photo/Ed Andrieski) The walking tour covers just over one and a half miles and takes up to two hours to complete. The tour is also available as an all-inclusive adults-only option, with complimentary drinks at several bars along the route and an EMF meter provided for each guest. The ghost tour is operated by Best Tours of Denver, which also offers historical and holiday lights tours. Some other tours in the top 10 include a New Orleans, Louisiana Adults-Only Ghost, Voodoo and Vampire Tour; the Dark Philly Adult Night Tour in Philadelphia, Pennsylvania; Haunted Booze and Boos Ghost Walking Tour in Charleston, South Carolina; and the History and Haunts Candlelit Ghost Walking Tour in Savannah, Georgia.