The nearest better known place would be Cisco, Utah.
St. Thomas is an interesting ghost town because it was abandoned two different times. It was settled by Thomas Smith in 1865 and grew to over 500 people but six years later a new survey moved the state line and made it so St. Thomas was in Nevada – Nevada ordered the payment of back taxes which the people could not afford and they left. Others came in and took up living there but in the 1930’s the Hoover Dam was built and raised the water line to cover the town, causing it to be abandoned again. Later the waters receded and the ruins were uncovered.