Our 15-county Region Spans Through Illinois and Missouri
Population numbers are derived from the U.S. Census Bureau’s County Population Totals: 2010-2019.
Illinois Counties
Bond County
One of two easternmost counties in the region, Bond is dominated by agriculture, but the county also has successful resort and outdoor sport industries thanks to local Carlyle Lake.
Population 16,426
Calhoun County
Catch a ferry — a major mode of transportation for Calhoun — to reach parts of this small, picturesque county, located on a peninsula between the Mississippi and Illinois Rivers.
Population 4,739
Clinton County
Located south of Bond County on the easternmost edge of the region, Clinton County has a larger, rural population that benefits from Carlyle Lake’s resort industry.
Population 37,562
Jersey County
Jersey County, bordered on the west by the scenic Great River Road and the Mighty Mississippi, offers beautiful views and destinations for locals and tourists.
Population 21,773
Macoupin County
Drive north on Interstate 55 to reach Macoupin County, which sits halfway between St. Louis and Springfield, Illinois. Macoupin’s economy runs on agriculture.
Population 44,926
Madison County
One of the largest counties in the region, much of Madison’s population and employment is centered in the county seat, Edwardsville, and other larger cities like Alton, Collinsville and Granite City.
Population 262,966
Monroe County
Monroe County sits at the southernmost end of the region and offers easy access to the City of St. Louis via Interstate 255 and the Jefferson Barracks Bridge.
Population 34,637
St. Clair County
A more populated county located just across the river from the City of St. Louis, St. Clair is home to both Scott Air Force Base and MidAmerica St. Louis Airport.
Population 259,686
Missouri Counties
Franklin County
Here, manufacturing is the dominant industry, primarily in the city of Washington, but the small farms and wineries dotting the county’s picturesque landscape also contribute to the economy.
Population 103,967
Jefferson County
Located just south of St. Louis County and bordered on the east by the Mississippi River, county residents can easily access Memphis, St. Louis and Chicago via Interstate 55.
Population 225,081
Lincoln County
Beautiful Lincoln County is home to both a state park and a Mississippi River conservation area. Its growing population supports predominantly manufacturing and service industries.
Population 59,013
St. Charles County
One of the fastest growing counties in the country, St. Charles boasts a booming economy featuring a cross-section of industries.
Population 402,022
City of St. Louis
The most densely populated and industrial county in the region, St. Louis City is a cultural, geographic and transportation nexus, home to both manufacturers and corporate headquarters.
Population 300,576
St. Louis County
The most populous county in the region, suburban St. Louis County is home to Clayton, the region’s county seat, which has abundant corporate offices and service businesses.
Population 994,205
Warren County
Primarily agricultural, Warren County shares a southern border with the Missouri River, can be accessed via Interstate 70, and offers picturesque land and conservation areas.
Population 35,649