Haycock Township was established in 1763 and was formed from "odds and ends" that were left over after all the surrounding townships had formed. The area that became Haycock was populated and had some roads, including Old Bethlehem Road, but there was no government to levy taxes and maintain roads and order. The name was derived from the conical shaped stacks of hay in fields that were call haycocks.

Haycock Township contains 2010 acres of State Game Lands, including Haycock Mountain, also within the Township are the 500 acre Lake Towhee County Park, and a large part of Lake Nockamixon State Park.