Gibraltar Rock

State Natural Area (No. 73)

Location: Columbia County. T10N-R8E, Sections 13, 18. 68 acres.

Access: From Lodi, go north on State Highway 113 four miles, then west on County V one mile, then south on Gibraltar Rock Road 0.2 mile to a parking area and gated access lane. Walk south up the steep and winding lane 0.5 mile to the bluff top.

Description: Rising 200 feet above the surrounding landscape, Gibraltar Rock is a flat-topped butte, an outlier of the Magnesian escarpment. With a thin Platteville-Galena dolomite cap over St. Peter sandstone, the butte offers panoramic views of the Wisconsin River Valley and Lake Wisconsin. Soils are thin, glaciated sandy loams. On the south is a sheer rock face overlooking a large leather-leaf bog and scenic valley. A major portion of the site is a dry mesic forest dominated by red oak and basswood. Cliff communities are mostly open and harbor several species of ferns, pale corydalis, columbine, and cliff goldenrod. On the bluff top is an area dominated by red cedar with an understory of dry prairie. Species include big and little blue-stem, side oats grama, prairie drop-seed, blue eyed grass, bird's foot violet, pasque flower, prairie smoke, lead-plant, bergamot, whorled milkweed, goldenrods, and asters. The site is used by migrating raptors, which catch thermals formed by the warm cliff face. Gibraltar Rock was originally owned by Columbia County, which transferred ownership to the DNR in 2007. It was designated a State Natural Area in 1969.