In 1903, the spring was enclosed by concrete and coquina walls that included multiple water gates and galleries to prevent water intrusion from river flooding. A four-story wooden bathhouse was constructed around the spring. The structure was designed by the Jacksonville architectural firm McClure & Holmes for owner Minnie Mosher Jackson, and included doctors' offices for patient examination and treatment, dressing rooms, space for concessions, and an elevator. At the time, water flow was calculated at 32,400 gallons per minute, or nearly 47 million gallons per day.