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