Within the park boundaries lies a ghost town that was inundated when Lake Mead first filled up in the 1930’s. Once a Mormon settlement, St. Thomas thrived as a stopping point between Los Angeles and Salt Lake City along the Arrowhead Trail.
Today, remnants of the town can now be seen thanks to the lowering water levels of Lake Mead, which is due to severe drought conditions. Once the town was flooded higher than 60 feet above the tallest structure, now visitors can roam the ghost remains of a true western town. St. Thomas lies in the northern part of the park near the Overton Arm along the Muddy River, which feeds into Lake Mead. The access road is dirt and sometimes bumpy so visitors with low riding vehicles may want to be careful. However most vehicles should be able to handle the approximately three mile dirt road. There is a dirt trail leading to the town site from the parking area.