 A 1962 United States Atomic Energy Commission report found children living in St. George, Utah, at the time of the fallout may have received doses to the thyroid of radioiodine as high as 120 to 440 rads" (1.2 to 4.4 Gy).According to the United States Census Bureau, the city has a total area of 64.9 square miles (168.0 km²), of which, 64.4 square miles (166.8 km²) of it is land and 0.5 square miles (1.2 km²) of it (0.72%) is water.St.