For sites that are located within the city limits of Saint Mary, Missouri. General Information: County: Sainte Genevieve County Zip Code: 63673 Area Code: 573 Population: 377 Latitude: 37.876153 Longitude: 89.948811 Median age: 39 years 100 females: 106 males Median household income: $27,000 Median family income: $31,964 Males median income: $34,375 Females median income: $14,583 Per capita income: $16,825. 13.2% of the population and 7.9% of families are below the poverty line. Nearest city with pop. 50,000+: St. Louis, MO (55.8 miles, pop. 348,189). Nearest city with pop. 1,000,000+: Chicago, IL (315.4 miles, pop. 2,896,016). Nearest cities: Chester, IL (9.0 miles), Ellis Grove, IL (9.7 miles), Ste. Genevieve, MO (9.8 miles), Perryville, MO (11.7 miles), Evansville, IL (14.8 miles), Prairie du Rocher, IL (17.5 miles), Ruma, IL (18.1 miles), Bloomsdale, MO (21.5 miles).