Hello Mr. Owens,
According to the book 23rd Battalion Virginia Infantry by J. L. Scott, William Surber is buried in the McClure Cemetery in Smyth County. He is not listed in the McClure Cemetery in the following link...unmarked perhaps?
http://www.newrivernotes.com/smythcem/mcclurecem.htm
See also:
http://www.worldcatlibraries.org/oclc/25105524&referer=brief_results