Part of an eastward extension of the Hellam Hills, Chickies Ridge has been separated from them by a water gap cut by the Susquehanna.

The ridge is composed of uplifted Cambrian Chickies Formation,[1] which extends several miles east before merging into the surrounding uplands.

During the Gettysburg Campaign of the American Civil War, Chickies Rock served as a Union army observation post during the Confederate occupation of Wrightsville across the river.

This was an amusement park built by the trolley company on the west end of the ridge, atop Chickies Rock, overlooking the Susquehanna.

A trolley car descending the steep Chickies grade to Columbia lost its brakes and derailed resulting in six deaths (including the motorman) and 68 injuries on August 9, 1896.