North Branch Kishwaukee River

Seneca Township is located in McHenry County, Illinois. As of the 2020 census, its population was 2,893 and it contained 1,102 housing units.

Franklinville is an unincorporated community and census-designated place in McHenry County, Illinois, United States. It was named a CDP before the 2020 census, at which time it had a population of 38.

Marengo Community High School is a public high school located in southwestern McHenry County, Illinois, that serves the communities of Marengo and Union, as well as the surrounding rural areas. The school has an enrollment of approximately 800 students.The softball team won the IHSA Class 3A state championship in 2017.

Marengo is a city in McHenry County, Illinois, United States on the Kishwaukee River. It lies approximately 60 miles west northwest of Chicago and approximately 30 miles east of Rockford. Per the 2020 census, the population was 7,568.

The Orson Rogers House is listed on the National Register of Historic Places and located in the McHenry County, Illinois city of Marengo. The property consists of several outbuildings, currently and in the past, as well, those buildings are and were mostly agriculture related.

The Charles H. Hibbard House, in the McHenry County city of Marengo, Illinois, has been listed on the National Register of Historic Places since 1979. The home, also known as the Cupola House, stood unoccupied on Grant Highway as of January 2007. In recent years the home had been classified by the Landmarks Preservation Council of Illinois (LPCI) as one of the state's threatened landmarks. In 2003 the property was listed on LPCI's "top ten most endangered" list. Some time after its 2003 the home underwent some renovation and no longer appears dilapidated on its exterior, as it did in a 2003 photo featured by the LPCI. In 2003 the house was listed as a landmark by the city of Marengo.

Coral Township is located in McHenry County, Illinois. As of the 2020 census, its population was 3,638 and it contained 1,380 housing units.

Marengo Township is located in McHenry County, Illinois. As of the 2020 census, its population was 7,202 and it contained 3,065 housing units. Marengo is a city located in the township.

Northwestern Medicine Woodstock Hospital (formerly Centegra Hospital - Woodstock) is a hospital in Woodstock, Illinois. The hospital is a division of Northwestern Medicine since 2018 when Northwestern Medicine partnered with Centegra Health System.

Hartland, elevation 922 feet (281 meters), is an unincorporated community and census-designated place in McHenry County, Illinois, United States. It was named a CDP before the 2020 census, at which time it had a population of 157.

Woodstock High School is a public high school located in Woodstock, Illinois, a part of Woodstock Community Unit School District 200. Established in 1921, it has an enrollment of approximately 1,050 students.

Harmony is an unincorporated community and census-designated place in McHenry County, Illinois, United States. Harmony is located on U.S. Route 20, 5 miles (8.0 km) west-southwest of Huntley. It was named a CDP before the 2020 census, at which time it had a population of 20.