Shamrock Township was created between 1876 and 1897, per official county maps from these two years, from the northeast 1/4 (approximately) of what before then was a much larger Nine Mile Prairie Township.
It's named for the shamrock, a national symbol of Ireland.[4]
Geography
Shamrock Township covers an area of 42.97 square miles (111.3 km2) and contains no incorporated settlements, although the unincorporated village of Shamrock.
The streams of Appling Branch, Bachelor Creek, Brushy Branch, Harrison Creek, Heat String Creek and Morris Branch run through this township, which also contains three cemeteries named Augusta, Chatman, and Sawyers.
The township is bordered on the west by Jackson Township (Auxvasse), on the south by Nine Mile Prairie Township (Williamsburg), on the north by Audrain County, and on the east by Montgomery County.
