Videotaped oral history interview with John Clark. A longtime maintenance manager with Dallas County, Clark has worked with county-owned buildings in the Dealey Plaza area since 1981. He was involved in air conditioning, lighting and other facilities work during the early days of The Sixth Floor exhibit.Interview conducted at The Sixth Floor Museum at Dealey Plaza on October 25, 2010 by Stephen Fagin. The interview is twenty-three minutes long.