Sull grew up in Petersburg, WV and graduated from Glenville State College with degrees in History and Business. He has resided in Oakland, MD for over 30 years where he is a partner in Highland Engineering.

Sull was appointed to the CVI Board of Directors in 1999 and has served as vice-president since 2001.

Sull is a charter member of the Youghiogheny Chapter of Trout Unlimited, is a member of the Youghiogheny River Watershed Association, and the Potomac-Garrett State Forest Advisory Board, served two terms on the board of directors of The Ruth Enlow Library and has been a member of the MD DNR Outdoor Caucus.