Ascension St. Vincent's Clay County Hospital. Hospital/Medical Center; Imaging; Mammography; Address. 1670 St. Vincent's Way Middleburg, FL 32068. Phone. 904-602-1000 Hours. 24 hours a day, 7 days a week. Appointments. 904-602-2600 ... Our facilities are currently taking precautions to help keep patients and visitors safe, which may include ....