From the record
“The Sulphur Well Historic District is an 81 acres (33 ha) historic district in Sulphur Well, Kentucky which was listed on the National Register of Historic Places in 1998.”
Wikipedia article Sulphur Well Historic District, CC BY-SA 4.0.
One of 5 National Register listings published here for Metcalfe County · listed in 1998 · category: District.
Sources: the Wikipedia article · the case file at the National Archives · the National Register database, National Park Service