McHenry County Government
![McHenry County logo](https://www.allianceforwaterefficiency.org/sites/default/files/styles/member_logo/public/member_logos/McHenry_County_Government-logo_0.png?itok=RBLJHqxk)
McHenry County is a county located in the U.S. state of Illinois. According to the 2010 census, it had a population of 308,760, making it the sixth-most populous county in Illinois. Its county seat is Woodstock.
McHenry County is a county located in the U.S. state of Illinois. According to the 2010 census, it had a population of 308,760, making it the sixth-most populous county in Illinois. Its county seat is Woodstock.