Welcome to Seneca Township


Seneca Township Building is located at 16506 Garden Valley Rd., Woodstock, Il.

The Township Board consists of a Supervisor, four Trustees, a Highway Commissioner, an Assessor, and a Clerk.

Township phone number is (815) 923-2288.

If you have an issue you would like addressed at a meeting, you must contact Supervisor Josh Brown at [email protected] ┬áno less than 48 hours prior to the meeting in order to be put on the agenda.

Seneca Township is one of 17 townships in the County of McHenry, IL. We are approximately 50 miles northwest of Chicago. The township is primarily agriculture with a growing residential presence moving into the township from the cities of Woodstock, Union, and Marengo.

Seneca Township was first settled by European-Americans in 1835 and officially became a township in 1850. The township was named for the Seneca Indians in New York State where many of the early settlers were from.

The north and south branches of the Kishwaukee River run through the township, joining in the southwest quadrant and continuing to flow westward. Kishwaukee is an Indian name meaning “clear waters” or “the place of sycamores.” The township land can generally be described as gently rolling and productive. However, early in the 1800’s the west side was heavily timbered, thus providing good hardwood for buildings and fuel for area residents.

Originally, Seneca Township had no towns located within its boundaries. At one time, the area known as “Franklinville” boasted several stores, a school, and post office (called Belden). At that time there was hope for growth in Franklinville, but when the railroad came to McHenry County it went to Union first, thereby discouraging the growth of Franklinville. At present, portions of the township that have some subdivision housing are annexed to the towns of Marengo and Woodstock. There are also small clusters of houses throughout the township, as well as many five, ten and twenty acre lots with houses.