Mount Pleasant Township was formed in 1818 from Fishingcreek Township, Greenwood Township, and Bloom Township, which is now Bloomsburg. The Wanich Covered Bridge No. 69 was listed on the National Register of Historic Places in 1979.
The township is located northwest of the center of Columbia County, and is bordered to the south by the town of Bloomsburg, the county seat. Fishing Creek, a tributary of the Susquehanna River, forms the southern and part of the eastern boundary of the township, while Little Fishing Creek forms the western boundary. The township includes the unincorporated communities of Welliversville, Mordansville, and Millertown.