Halfmoon Township is a township in Centre County, Pennsylvania, United States. It is part of the State College, Pennsylvania Metropolitan Statistical Area. The population was 2,667 at the 2010 census, which is a 13.2% increase since the 2000 census.
Halfmoon Township, settled in 1784, was formally erected in 1802. It is said to be named for marks cut on trees along a Native American trail that was located at the base of Bald Eagle Ridge.
Found at http://www.centrecountyhistory.org/history/newtour.html Centre County Historical Society site.