During the summer of 1851, a small company of men was exploring this area and discovered the springs on the bench one-fourth mile to the east. Joel H. Johnson was so impressed with the spot, that he sought and received permission from George A. Smith to build a house and corral at the springs and care for the cattle belonging to the settlers of Iron County. In 1854, Brigham Young called other families to assist in this endeavor and to help build a fort for protection. The fort was named after Johnson who built his home inside the fort.
The fort was 10 rods square (165' x 165'). The 9' high walls, made of clay, were 2 1/2' thick at the bottom and 18" thick at the top. There was a large gate made of logs on the north side and a smaller gate on the south. For drinking water a well was dug in the center of the fort. Apple orchards and vegetable gardens were planted. A large two-story building, called the Bastion, was built with portholes for defense. Some of the cottonwood trees planted near the fort, now enormous, survive to this day.
In 1881, the fort became a mail station between Milford and Silver Reef. Ownership of the fort has changed many times. It was always a favorite gathering place for holiday celebrations like the 4th and 24th of July and May Day.
Some remains of the fort are visible one-half mile north of this marker.