Question: Hoe many locations does the organization taking care of the Talking Rocks cavern operate in the US?

full_context: Document 1: Rock City (attraction): Rock City is a roadside attraction on Lookout Mountain in Lookout Mountain, Georgia, located near Ruby Falls. It is well known for the many barn advertisements throughout the Southeast and Midwest United States that have the slogan "See Rock City" painted on roofs and sides. Clark Byers painted over 900 barn roofs in nineteen states to advertise for Rock City from 1935 to 1969.
Document 2: Heritage USA: Heritage USA is a former American Christian theme park, water park, and residential complex built in Fort Mill, South Carolina by PTL Club (short for "Praise The Lord") founders televangelist Jim and Tammy Faye Bakker.
Document 3: Mystic Caverns and Crystal Dome: Mystic Caverns and Crystal Dome are show caves located between the cities of Jasper and Harrison, in the state of Arkansas, U.S., on the Arkansas Highway 7 Scenic Byway near the defunct amusement park Dogpatch USA. Sometimes called "the twin caves" because they are within 400 ft of each other, the two caves maintain a year-round temperature of 58 °F, contain more formations per foot than any other caves in Arkansas, and are open for public tours year-round except during the January flooding season.
Document 4: Mark Twain Cave: Mark Twain Cave — originally McDowell's Cave — is a show cave located near Hannibal, Missouri, USA. It is the oldest operating show cave in the state, giving tours continuously since 1886. Along with nearby Cameron Cave, it became a registered National Natural Landmark in 1972, with a citation reading "Exceptionally good examples of the maze type of cavern development". Mark Twain Cave — as "McDougal's Cave" — plays an important role in the novel "The Adventures of Tom Sawyer" (1876) by Mark Twain and was later renamed in honor of the author, a Hannibal native.
Document 5: Family Kingdom Amusement Park: Family Kingdom Amusement Park is a seaside amusement park in Myrtle Beach, South Carolina. Located on Ocean Boulevard, in the heart of Myrtle Beach, the amusement park has 37 rides for adults and children of all ages, including thrill rides, family rides, kiddie rides and go karts. In 2007, TripAdvisor ranked it at number five on its list of the top 10 amusement parks outside Orlando.
Document 6: Rock City, Kansas: Rock City is a park located on hillsides overlooking the Solomon River in Ottawa County, Kansas. It is 3.6 miles south of Minneapolis, Kansas and just over 0.5 mile west of Kansas highway K-106 and the Minneapolis City County Airport on Ivy Road. In a patch of prairie about 500 meters (1600 feet) long and 40 meters (130 feet) wide, Rock City contains three clusters of large spherical boulders. These three clusters contain a total of 200 spherical boulders. It has been designated as a National Natural Landmark.
Document 7: Six Flags: Six Flags, officially Six Flags Entertainment Corporation, is an amusement park corporation based in the United States, with properties in the US, Canada, and Mexico. It is the largest amusement park company in the world, based on the number of properties owned, and is ranked sixth in terms of attendance. The company maintains twenty properties throughout North America including theme parks, thrill parks, water parks, and family entertainment centers. In 2016, Six Flags properties hosted over 30.1 million guests.
Document 8: SeaWorld Parks &amp; Entertainment: SeaWorld Parks & Entertainment is a family entertainment, amusement park and attraction company headquartered in Orlando, Florida. It operates seven theme parks and five water parks in the United States.
Document 9: Knoebels Amusement Resort: Knoebels Amusement Resort ( ) is a family-owned and operated amusement park, picnic grove, and campground in Elysburg, Pennsylvania. It is and has been America's largest free-admission park for 90 years of operation. Opened in 1926, the park has more than 60 rides, three wooden roller coasters, one steel roller coaster, a 1913 carousel, and a haunted house dark ride that was featured on the Discovery Channel. The park and its rides have won awards from organizations such as "Amusement Today", American Coaster Enthusiasts, and the International Association of Amusement Parks and Attractions. In 2014, Travel Channel rated Knoebels one of their Top 10 Family Friendly Amusement Parks in the United States. America's Number One Amusement Park
Document 10: Herschend Family Entertainment: Herschend Family Entertainment (HFE) is a privately owned themed-entertainment company that operates several theme parks and tourist attractions within the United States.
Document 11: Table Rock State Park (Missouri): Table Rock State Park is a state park in the U.S. state of Missouri consisting of 356.03 acre located in Taney County and Stone County on Table Rock Lake along the southern side of the city of Branson. Park facilities include a marina, campgrounds, and trails for hiking and bicycling.
Document 12: Six Flags: Six Flags, officially Six Flags Entertainment Corporation, is an amusement park corporation based in the United States, with properties in the US, Canada, and Mexico. It is the largest amusement park company in the world, based on the number of properties owned, and is ranked sixth in terms of attendance. The company maintains twenty properties throughout North America including theme parks, thrill parks, water parks, and family entertainment centers. In 2016, Six Flags properties hosted over 30.1 million guests.
Document 13: Talking Rocks Cavern: Talking Rocks Cavern (originally called Fairy Cave) is a cavern system located in Stone County, just west of Reeds Spring in the U.S. state of Missouri. It is privately operated by Herschend Family Entertainment as a tourist attraction.
Document 14: Family entertainment center: A family entertainment center (or centre), often abbreviated FEC in the entertainment industry, (also known as indoor amusement park or indoor theme park) is a small amusement park marketed towards families with small children to teenagers, and often entirely indoors or associated with a larger operation such as a theme park. They usually cater to "sub-regional markets of larger metropolitan areas." FECs are generally small compared to full-scale amusement parks, with fewer attractions, a lower per-person per-hour cost to consumers than a traditional amusement park, and not usually major tourist attractions, but sustained by an area customer base. Many are locally owned and operated, although there are a number of chains and franchises in the field. FECs are sometimes called family amusement centers, play zones, family fun centers, or simply fun centers. Some non-traditional FECs, called urban entertainment centers (UECs), with more customized and branded attractions and retail outlets, are associated with major entertainment companies and may be tourist destinations. Others, sometimes operated by Non-Profit organizations as Children's Museums or Science Centers, tend to be geared toward edutainment experiences rather than simply amusement. FECs may also be adjuncts to full-scale amusement parks.
Document 15: Cascade Caverns: Cascade Caverns is a historically, geologically, and biologically important limestone solutional cave 3 mi south of Boerne, Texas, United States, on 226 Cascade Caverns Road, in Kendall County. It has been commercially operated as a show cave and open for public tours since 1932. Informal tours were run as far back as 1875 when Dr. Benjamin Hester owned the cave property. The cave was known by the native Lipan Apache people who lived in the area prior to 1800.
ground_truth: several theme parks