Sterling Barrens

State Natural Area (No. 147)

Location: Within Governor Knowles State Forest, Polk County. T36-R19W, Sections 4, 5, 31, 32. T36N-R20W, Section 34. 1022 acres.

Access: From the intersection of Highways 87 and N in Cushing, go west on 87 0.7 mile, then continue west on 250th Avenue 3 miles, then north on 280th Street 1.5 miles, then west on Evergreen Avenue 3 miles, then south on 320th Street 2.25 miles to the northeast corner of the site.

Description: Located in pitted outwash deposits laid down by glacial melt-water streams, Sterling Barrens contains a jack pine-Hill's oak dry forest interspersed with barrens openings and an extensive wetland of sedge meadow and shrub-carr. The gently rolling barrens openings are interspersed with prairie species. Dominant grasses are needle grass, three-awn grass, Indian grass, and big and little blue-stem. Several rare forbs are at or near their natural eastern range limit. Included in the natural area are the St. Croix River terrace escarpment and a reach of the St. Croix that contains an excellent diversity of aquatic species. The river is lined with bottomland hardwoods of silver maple, elm, black ash, and cottonwood with willow brush. Many dragonfly species are found in this portion of the river. The dry forest on the sandy uplands and the terrace slope is young but has a diverse groundlayer. Adjacent to the river is a sedge meadow dominated by wide-leaved sedges, prairie cord grass, marsh fern, sensitive fern, blue-joint grass, wool grass, ironweed, and Joe-pye weed. Shrub-carr areas consist primarily of willows with white meadowsweet, alder, and occasional tamarack. Low areas support stands of emergent aquatics including arrowhead, cat-tail, three-way sedge, river bulrush, hardstem bulrush, and spike rushes. Breeding bird surveys show broad winged hawk, red-eyed vireo, chestnut-sided warbler, ovenbird, and chipping sparrow as common nesters. Sterling Barrens is owned by the National Park Service and DNR. The site was originally designated a State Natural Area in 1979 and later expanded to include the St. Croix Scenic Riverway in 2002.