Kelleys Island State Park East Quarry’s main entrance is about a mile East of Division on Ward Road. Additional entrances for hikers can be found on Monagan and Woodford Roads. This quarry was part of a much larger quarry to the west of Division. The Kelleys Island Lime and Transport Company began quarrying this area around 1933 and continued until 1940. The quarry started at Division Street and ended at the head of Horseshoe Lake. The quarried material was hauled west under a bridge on Division Street via a narrow gauge railway. Some of the tracks of the abandoned rail line can still be seen beneath the waters of the lake.

Horseshoe Lake is a rapidly aging lake abundant with plant, fish and aquatic life. Hikers and many wildlife species use the trails around the lake. The several miles of trails afford hikers a spectacular view of Kelleys Island’s trees, wildflowers, glacial markings and fossil preserves. The quarry at one time was the bottom of the Devonian Sea. Scattered throughout is a marvelous record of the marine, invertebrate animals, which abounded on the floor of the sea. Here you can find fossil remains of corals, brachiopods, gastropods, pelecypods, cephalopods, crinoids and stomato-poroids. Glacial scraping marks can also be seen on the upper edges of the quarry and an abundant variety of birds have been spotted from Horseshoe Lake.

Among the trees along the East Quarry trails, are: The American basswood, a highly regarded timber tree that was used by Native Americans to make rope by first soaking the bark in water to remove the non-fibrous portions; osage-orange is the single species of its genus and was originally restricted to the southern U.S.; black cherry, a beautifully colored wood used for fine furniture and cabinets; hackberry, honey locust, chinquapin oak; and the eastern hop hornbeam or "weed tree", which is distinguished from other trees by its bark which has a shreddy appearance with broken shaggy plates that curve away from the trunk.

The remnants of old fence lines in the East Quarry are typical on Kelleys Island. Due to the shallow soil in most areas, islanders used barrels filled with rocks to hold the fence posts. There are several areas on the island where remains of these fence lines can be seen. Also visible near the trails in the East Quarry are fences made of rocks gathered by the farmers when they cleared the fields for planting in the late 19^th and early 20^th Centuries.