In 1910 the US Census Bureau calculated the nation's mean population center to lie in Monroe County.

[3] Monroe County is part of the Bloomington, Indiana, Metropolitan Statistical Area.

[16] The county terrain is low rolling hills, covered with vegetation and largely devoted to agricultural use or urban development.

The eastern part is carved with drainages and gullies, leading to Griffy Lake.

[17] The county's highest point is McGuire Benchmark, just NW of Bloomington, at 994 ft (303 m) ASL.

[19] The northern part drains to the West Fork; the southern part of the county drains to the East Fork, primarily via the Salt Creek and its tributaries, such as the Clear Creek (known as the "Jordan River" on Indiana University Bloomington campus).

The largest is Monroe Lake, a large reservoir on Salt Creek in the southeastern part of the county.

A smaller lake, Weimer (Wapehani) in the Clear Creek basin, was constructed for water supply purposes, but during most of its history was used purely for recreation - mainly fishing.

[23] In 2017 authorities revealed plans to drain this lake permanently, as it was considered to be unsafe.

[25] A number of abandoned limestone quarries in the county are now cliff-surrounded lakes (as seen in the 1979 film Breaking Away), stable without ongoing human intervention.

The commissioners are charged with setting policy and managing the day-to-day functions of the county government.

[31] Monroe County is part of Indiana's 9th congressional district and is represented in Congress Republican Trey Hollingsworth.

In 2008, Barack Obama won the county by the largest margin for a Democrat running for president since 1912.

President Obama also became the first Democrat since Franklin Pierce in 1852 to win the county with over 60% of the vote.

Monroe County Public Library operates branches at Bloomington and Ellettsville.

Between 1854 and 2004, an important north–south line connecting the Ohio River with Lake Michigan crossed Monroe County as well, serving Stinesville, Elletsville, Bloomington, Smithville, and Harrodsburg.