Mermentau Branch Mailing Address PO Box 369 Mermentau, LA 70556 Physical Address 107 Second St. Mermentau, LA 70556 Phone: 337-824-0690 HOURS OF OPERATION Tuesday & Thursday 1:00 PM – 5:00 PM Get Directions For Driving Walking Bicycling show options hide options Avoid Tolls Avoid Highways From To Fetching directions...... Reset directions Print directions