| St. Charles County is a county located in the | | | | residing in the county. The population |
| U.S. state of Missouri. As of 2000, the | | | | density was 196/km² (507/mi²). There |
| population was 283,883. Saint Charles County | | | | were 105,514 housing units at an average |
| is part of the St. Louis Metro Area. Its | | | | density of 73 persons/km² (188 persons |
| county seat is Saint Charles6. The county was | | | | mi²). The racial makeup of the county was |
| organized in 1812 and named for the Spanish | | | | 94.67% White, 2.69% African American, 0.23% |
| district once located here, San Carlos, from | | | | Native American, 0.85% Asian, 0.03% Pacific |
| Saint Charles Borromeo. | | | | Islander, 0.46% from other races, and 1.07% |
| | | | from two or more races. Hispanic or Latino of |
| Geography | | | | any race were 1.47% of the population. |
| | | | |
| The county has a total area of 1,534 km² | | | | There were 101,663 households out of which |
| (592 mi²). 1,451 km² (560 mi²) of it | | | | 40.50% had children under the age of 18 |
| is land and 83 km² (32 mi²) of it | | | | living with them, 63.20% were married couples |
| (5.39%) is water. | | | | living together, 9.20% have a woman whose |
| | | | husband does not live with her, and 24.20% |
| Adjacent counties | | | | were non-families. 19.40% of all households |
| | | | were made up of individuals and 5.90% had |
| Lincoln County (northwest) | | | | someone living alone who was 65 years of age |
| | | | or older. The average household size was 2.76 |
| Calhoun County, Illinois (north) | | | | and the average family size was 3.18. |
| | | | |
| Jersey County, Illinois (northeast) | | | | In the county the population was spread out |
| | | | with 29.00% under the age of 18, 8.20% from |
| Madison County, Illinois (east) | | | | 18 to 24, 32.60% from 25 to 44, 21.60% from |
| | | | 45 to 64, and 8.80% who were 65 years of age |
| St. Louis County (southeast) | | | | or older. The median age was 34 years. For |
| | | | every 100 females there were 97.10 males. For |
| Franklin County (south) | | | | every 100 females age 18 and over, there were |
| | | | 94.10 males. |
| Warren County (west) | | | | |
| | | | The median income for a household in the |
| Major highways | | | | county was $57,258, and the median income for |
| | | | a family was $64,415. Males had a median |
| Interstate 64 | | | | income of $44,528 versus $29,405 for females. |
| | | | The per capita income for the county was |
| Interstate 70 | | | | $23,592. 4.00% of the population and 2.80% of |
| | | | families were below the poverty line. Out of |
| U.S. Route 40 | | | | the total people living in poverty, 4.90% are |
| | | | under the age of 18 and 5.10% are 65 or |
| U.S. Route 61 | | | | older. |
| | | | |
| U.S. Route 67 | | | | St. Charles County, with a population of |
| | | | 337,572, has been one of the fastest-growing |
| Route 79 | | | | counties in the country for decades, with 55 |
| | | | percent growth in the 1980s, 33 percent in |
| Route 94 | | | | the 1990s, and another 13 percent between |
| | | | 2000 and 2004. The county features a |
| Route 364 | | | | cross-section of industry, as well as |
| | | | extensive retail and some agriculture. With |
| Route 370 | | | | the Missouri River on the south and the |
| | | | Mississippi on the north and east, the county |
| Demographics | | | | is bisected east to west by Interstate 70. |
| | | | St. Charles County has two small airports and |
| As of 2000, there were 283,883 people, | | | | two ferries that cross the Mississippi River. |
| 101,663 households, and 77,060 families | | | | The City of St. Charles is the county seat. |