The cover photo is from the 1976 Clarendon history book and is what was known as the Horton Mill Dam. This dam was located on the Cold River immediately to the west of Route 7 where it crosses the river. Any remnants of the dam were likely removed during construction of the highway in 1966/67.
The Horton Mill was owned by Bent Earl Horton (1848 - 1906), Bent being his mother's maiden name. The transcript here of a newspaper article about the fire notes other businesses that the fire spread to. The newspaper article suggests the fire was deliberately set. Bent's wife and son mentioned in the article were Ella Georgiana Gould (1851 - 1915) and Guy Bertram Horton (1875 - 1950).