This fascinating natural area is situated in southern Fairfield County, five miles southeast of Lancaster. This region has been known by naturalists for its biological diversity for many years. Dedicated in April of 1996, Rhododendron Cove is significant for having the highest concentration in Ohio of the native great rhododendrons, a state endangered species.
About 175,000 years ago, the massive glacial wall of the Illinoian ice stalled just to the north of the Black Hand Sandstone which makes up Rhododendron Cove.As the climate moderated, meltwaters rushing southward deposited silt and gravel in the old pre-glacial Logan River Valley and adjacent coves and side valleys.Nearby, Pump Station Road is built upon one of these gravel terraces. The cove itself contains deposits of fine silts representing slack-water sedimentation.
The preserve is located within the Hocking Valley region, an area known for its Black Hand Sandstone features. Rhododendron Cove is a horseshoe-shaped ridge of Black Hand Sandstone overlain with a thin layer of Logan Sandstone. The Raccoon Shale is found at the very base of the cliffs. The sandstone is evident as one walks the preserve trails, large, fern-covered sandstone blocks rest at odd angles adjacent to the high-walled ridge. Bands of white quartz pebbles are interbedded in the brown-gray Black Hand Sandstone. The pock marked cliff faces reflect an erosional process known as "honeycomb weathering". The acidity of the sandstone-derived soils and the cool, moist environment within the cove are limiting factors to the types of plant communities and rare plants found here.
The Sugar Grove Region which includes Rhododendron Cove is one of the richest botanical regions in Ohio. Its flora may be described as an outlier of the Appalachian flora
found to the south and east. The population of Rhododendron maxima can be seen in peak bloom in late June to early July.
The stream valley within the cove provides a safe haven for many common wildflowers and plants of this region. Black cohosh, large-flowered trillium, wild geranium, and wide variety of violets are but a few of the numerous wildflower species. Wet seeps in the base of the cove, on its eastern side, create a wet meadow where skunk cabbage makes a late winter appearance.Other species in the seeps include golden saxifrage,
lady's tresses orchard, mountain mint, and wing stern. More than a dozen species of ferns grow in the preserve.
Rhododendron Cove State Nature Preserve is a very special place. Connected to the nearby road only by a narrow easement means that parking and access is very limited. To minimize the impact on the preserve and yet provide access to the general public to enjoy this natural area, visitation is permitted by written access permit from the Division of Natural Areas and Preserves, 1889 Fountain Sq. Court, Columbus, OH 43224 phone: