The incident happened at about 7 a.m.
Deputies said the man had no apparent connection to the Sheriff's office — he was not being booked into or released from the jail and had no open court cases.
The man parked his vehicle in the county highway department's parking lot and walked to an area near the sheriff's office where he died.
Deputies said his body will be taken for an autopsy while they continue to look into the incident.
For more information, pick up a copy of Thursday's Register.