Clinton Township is situated in the northern tier of townships bounded on the north by Clinton County, on the west by Washington Township, on the south by Center and on the east by Hamilton County. It contains thirty-three sections of land. Half sections 13 to 18 inclusive, and sections 19 to 36 inclusive, in township 20 north, range 1 east, and sections 1 to 12 inclusive, in township 19 north, range 1 east. Its surface is generally level, sloping gently towards the northwest. Section 12 in the southwest corner is the highest and most level in the township, and the northwest corner is the lowest and most broken.
Sugar Creek cuts off a small portion of the northwest corner.
Mud Creek, Terrapin Creek and Brown's Wonder all flow toward to northwest and drain the entire township into Sugar Creek. There is a story about the origin of the name of this latter creek. It is stated that when the surveyors were surveying this part of Boone County and came across the head waters of this stream in Center Township and it twisted and flowed in so many directions that much controversy arose among them as to where the creek would empty. It was no easy work to survey this wild land. To cut a way through the brush and wade through the bogs and lazy crooked streams was a tedious task.