The Mississippi River Gorge, in the heart of the Twin Cities, is one of the most significant features of the entire 2,350-mile long Mississippi River. Up until the early 1900s, when the river was modified to accommodate commercial navigation and generation of hydroelectric power, the river through the gorge was a series of impressive rapids. Water tumbled over boulders and limestone shelves formed by the migration of St. Anthony Falls upstream to its present location in Minneapolis. The cities of Minneapolis and St. Paul grew up around this unique area. Today, the land between bluffs on either side of the river is in Mississippi Gorge Regional Park, managed by the parks departments of Minneapolis and St. Paul. Many neighborhoods along this stretch of the Mississippi National River and Recreation Area are working to restore native habitat and improve recreational opportunities, with the help of state and federal agencies and nonprofit organizations.
The National Park Service is supporting one such project off 36th Street and West River Road, in the Longfellow neighborhood. Over the past five years, the National Park Service has provided $60,000 in matching funds to restore 5 acres of mesic oak savanna, one of the rarest native plant communities in Minnesota, and 5 acres of oak woodland. This type of habitat was once widespread throughout the Upper Midwest but has all but disappeared since European settlement. Fire suppression has prevented the periodic clearing of understory vegetation typical of oak savannas, and buckthorn and other invasive, exotic plants have crowded out native prairie species. In addition to restoring habitat, the Mississippi Gorge project is addressing erosion caused by heavy recreational use. The project has doubled the amount of mesic oak savanna in the metropolitan area.
Project partners—the Longfellow Community Council, Minneapolis Park and Recreation Board, and National Park Service—first developed a plan to guide restoration efforts. In keeping with this plan, buckthorn and other non-native woody plants, as well as some native trees, were removed to restore the openness of a mesic oak savanna forest. The stumps of the exotic species were treated with an herbicide to prevent regrowth. Following the clearing, resource specialists carried out prescribed burns each spring for three years to maintain the forest opening and allow prairie plants and shrubs to become reestablished. In the future, burns are scheduled for every other year to maintain the native habitat.
Measures have also been taken to reestablish vegetation on paths where it had been worn away and soil exposed from people traveling up and down the bluff, off designated trails, to access the river. In some places, erosion was so severe that gullies had formed and sediment was washing into the river during heavy rains. The gullies have been filled with soil and seeded with native grasses and flowers, with signs posted asking hikers and other recreationists to remain on the designated trails. In some places, temporary fences have been installed as an added protection measure. At steeper portions of the trails, erosion control bars and stairs are being installed.
All of this work has been accomplished with the help of volunteers, who have helped remove buckthorn, revegetate eroding areas, and collect seeds from mature prairie plants for use in future restoration projects. Their ongoing efforts to keep the area free of buckthorn and other invasive plants are critical to the project’s success.