Empire Prairies

State Natural Area (No. 146)

Location: Dane and Columbia Counties. T8N-R9E, Section 11. T8N-R8E, Section 27. T11N-R10E, Section 24. 139 acres.

Access: For the Westport Drumlin Prairie Unit: From the intersection of Highway 113 and County M, just north of Lake Mendota, go north on 113 1.7 miles, then east on Bong Road 0.8 mile to a walk-in access. See map for legal access on foot. For the Hagen Prairie Unit: From the intersection of State Highway 16 and County Trunk C in Rio, go south on C 2 miles, then west on Hanson Road 1 mile, then south on Hagen Road 0.18 mile. Park along the road and walk east along an old farm lane into the natural area. There is no legal public access to the Koch Prairie Unit at this time.

Description: Empire Prairies contains three dry to dry-mesic prairie remnants and a small oak opening that were once part of the extensive Empire Prairie stretching across southern Columbia and northern Dane counties. Oriented on a northeast to southwest-oriented glacially sculpted ridge is Westport Drumlin Prairie -- a small but diverse prairie containing more than 100 native plant species. A small area of oak opening, with open-grown bur oaks, occupies the western point of the ridge. Although the drumlin wears a thin mantle of glacial till, as evidenced by rounded boulders scattered about, limestone bedrock fragments and small outcrops at the drumlin’s summit attest to the limited terra-forming action of glacial ice on this ridge. Several showy plant species are present including pasque flower, cream wild indigo, rough blazing-star, yellow coneflower, shooting-star, bird’s-foot violet, compass plant, rosinweed, goldenrods, and asters. Dominant grasses are big and little blue-stem, Indian grass, side oats grama, needle grass, and prairie drop-seed. Populations of the federally-threatened prairie bush-clover (Lespedeza leptostachya) and the rare prairie false dandelion (Nothocalais cuspidata) are present. The red-tailed prairie leafhopper (Aflexia rubranura), a state-endangered insect that feeds exclusively on prairie dropseed, is also found here. Located within Mud Lake Wildlife Area, the Hagen Prairie Unit supports a diversity of plants. While most are typical dry-mesic species, wet-mesic species are also present including swamp milkweed and prairie blazing star. In spring, the site features an outstanding display of shooting stars. The Koch Prairie Unit is located on an isolated hill surrounded by cropland. The hill is dolomite bedrock with glacial till near its base. This dry-mesic remnant contains more than 60 native species and is dominated by prairie drop-seed. Empire Prairies is owned by the DNR and private landowners and was designated a State Natural Area in 1984.