Wintergreen Gorge is a six-mile long canyon in Harborcreek Township, which reachest depths of 250-feet at its highest point. It was carved from shale and sandstone by Fourmile Creek during the end of the last Ice Age more than 11,000 years ago. The gorge includes a partially mature forest community of county and state significance, in which there are two rare habitats that harbor plant species of special concern.
Great quantities of wintergreen (a small evergreen plant with a cluster of oval leaves, flowers and red berries) grew all along the great gully, giving this natural wonder its name.
Many miles of user-created trails have been developed over time by visitors to the Gorge. As these existing trails are based on desire lines, and do not typically take into account environmental issues or sustainable trail practices, a restoration effort, beginning with the development of the Wintergreen Gorge Sustainability Master Plan, was initiated in 2010. In September 2020, the first phase of this master plan was completed.
Location and Size
Wintergreen Gorge surrounds Fourmile Creek in Erie County. It is six-miles long, with a portion (3,980 feet) being located within the campus of Penn State Behrend. The gorge depth varies from 50 to 250 feet, gradually becoming shallower as it proceeds north from its origins a half-mile south of Wesleyville. Wintergreen Gorge was named for the American Wintergreen plant that was commonly found in the gorge.
The gorge was carved from shale and sandstone by Fourmile Creek. Despite its name, Fourmile Creek is approximately 8 miles in length, has a drainage basin of 11.93 square miles and is a part of the Lake Erie Watershed.
The headwaters of Fourmile Creek are located in Greene Township, immediately north of Pennsylvania Route 8. From its headwaters, the creek carves a valley that gets deeper as it flows northwest. After several miles, it turns northwards, crosses under Interstate 90, exits Greene Township and enters Harborcreek Township. Here the gorge surrounding the creek reaches its deepest point of 250-feet. Beyond this, the valley gets shallower as the creek flows under Pennsylvania Route 290, turns northwest and heads along the border between Harborcreek Township and the City of Erie. Upon entering the City of Erie, it continues northwest, passing through the Lawrence Park Golf Club and entering Lake Erie.
Topography & Erosion
Fourmile creek flows across a shale bed with scattered gravel deposits and small boulders. Several small waterfalls are spaced along the creek.
The gorge contains a significant amount of steep slopes (between 14-25%) and very steep slopes (>25%). As a result of this topography, the gorge entails a lot of soils, which are considered to be moderate-to-severely erodible.
Erosion is the number one problem for sustainable trails. Erosion is the natural process by which soil and other material is transported by wind or water. If left unchecked, erosion can quickly cause serious damage to trails and the very resources we are charged to protect. Trail erosion can be accelerated by seasonal conditions, weather patterns, trail use, use volume, use type, terrain, vegetative cover, and gravity to name a few. One can only mitigate trail erosion through the utilization of sustainable trail principles.
Geology
Fourmile Creek and the Wintergreen Gorge are located within two distinct physiographic proveniences and sections:
1. Northwestern Glaciated Plateau Section; and,
2. Central Lowland Province: Eastern Lake Section.
The Eastern Lake Section consists of a series of northwest-sloping, lake parallel, low-relief ridges. These ridges are made up of unconsolidated surficial materials, mainly sands and gravels, that were deposited during the most recent deglaciation of the area about 18,000 years ago. Steep sided, narrow valleys cut through these ridges into the underlying shales and siltstones and flow into Lake Erie.
Originally, the ridge bordering Lake Erie sloped gently into the lake. However, erosion of the shoreline has caused the lake-land interface to move southeastward so that today there is a steep bluff adjacent to the lake. Continued erosion of this bluff is a primary environmental problem in the area. Elevation is 570 feet at Lake Erie and rises southward to a height of 1,000 feet.
The Northwestern Glaciated Plateau Section consists of many broad, rounded uplands cut by long, linear valleys. The uplands have a southeast-oriented linearity that is pronounced in eastern Erie and central Crawford Counties. Elsewhere upland linearity is obscure to absent. The uplands are cut by many flat-floored, narrow to wide valleys that are separated from adjacent uplands by steep slopes on one or both sides of the valley. The valleys are very linear and are oriented north-west-southeast for the most part although some valleys are normal to this orientation. The valley floors are often wetlands.