Fort Pierce was built along this thoroughfare about twelve miles southeast of St. George near the Arizona border near the base of the Hurricane cliffs. The fort was used for just four years but portions of its rock walls can still be seen today. John D. L. Pierce was the captain of a cavalry troop that were charged to protect the new settlements and livestock from Indian raids during the Blackhawk War. He built the fort at the site of a spring and wash (both of which now bear his name.) At one point in 1865 it was reported that 20 to 30 men were guarding there. For many years after this the abandoned Fort Pierce was a watering place for travelers and their stock.

Historian Karl Larsen described the fort saying: "The fort was constructed as a rectangle, its length being well over thirty feet on the inside. One small window faces west, the door to the structure apparently being on the east side. There are two rooms, the one on the north being considerably the larger, while the remains of a crude fireplace are still to be seen in the south wall. Since there was no roof on the structure, about the most charitable thing one might say of the fort is that it served well as a wind-break. At the northwest and southeast corners flankers were built which communicated with the interior of the fort. Each flanker has four portholes at levels convenient for defense, one facing each direction, so that the approaches to the fort from any angle could be covered by the defenders. Additional portholes were placed in the main rectangle. The flankers are rectangular in shape with inside dimensions of about four by seven feet."