Tucked in the side of Conococheague Mountain, Big Spring State Park is a quaint picnic and hiking area. A short loop trail leads to a partially completed railroad tunnel with historic interpretation at the trailhead. The park also provides access to the Iron Horse Trail for day and overnight hiking. The park takes its name from nearby Big Spring, whose waters form the scenic Shermans Creek.

In the mid-1800s to the early 1900s, logging companies lumbered the area. Trees were hauled from the stump to the mill on the Perry Lumber Railroad. This narrow gauge railroad had a terminus at the east end of the park. The trees were cut to supply tanneries, barrel manufacturers and charcoal furnaces. A tannery near the spring operated from early in the 1800s until 1860. In 1871, an axe handle factory was started in the old tannery.

The Newport and Sherman's Valley Railroad laid tracks through the park to link to the Path Valley Railroad in Franklin County. Their tunnel through Conococheague Mountain failed and the Newport and Sherman's Valley Railroad went out of business.

During the early 1900s, the area was a community picnic area accessible by road and railroad. The Commonwealth developed the current facility in 1936 with Civilian Conservation Corps Camp S-111.