[3] Nearly bisected by the Muskingum River, the county name is based on a Delaware American Indian word translated as "town by the river"[4][5] or "elk's eye".

[10] Moravian missionary David Zeisberger wrote that the Muskingum River was called Elk's Eye "because of the numbers of elk that formerly fed on its banks.

As of the census[17] of 2000, there were 84,585 people, 32,518 households, and 22,860 families living in the county.

The racial makeup of the county was 93.91% White, 4.01% Black or African American, 0.21% Native American, 0.27% Asian, 0.02% Pacific Islander, 0.20% from other races, and 1.37% from two or more races.

24.90% of all households were made up of individuals, and 10.90% had someone living alone who was 65 years of age or older.

As of the 2010 United States Census, there were 86,074 people, 34,271 households, and 23,125 families living in the county.

[18] In terms of ancestry, 25.2% were German, 15.5% were Irish, 11.1% were American, and 10.9% were English.

The Ohio Anti-Slavery Society was originally created as an auxiliary of the American Anti-Slavery Society[23] and held its first meeting Putnam, Ohio, in April 1835.

This includes service to Dresden, Duncan Falls, New Concord, and Roseville.

[26] The Wilds is a 9,154 acres (37.04 km2) wildlife preserve open to visitation for a fee.