Olson Oak Woods

State Natural Area (No. 157)

Location: Within the Madison School Forest, Dane County. T5N-R8E, Section 5, 6. T6N-R8E, Sections 31, 32. 166 acres.

Access: From the intersection of U.S. Highway 151 and State Highway 69 in Verona, go south on Highway 69 about 1.2 miles, then west on Riverside Road 2 miles, then south on Fritz Road 1 mile to a parking lot east of the road.

Description: Olson Oak Woods lies about three miles west of the Johnstown terminal moraine on a divide between branches of the upper Sugar River. The large southern dry forest features white and black oaks with black cherry, bur oak, red oak, hickory, elm, and basswood. Scattered open-grown oaks dating to the 1750’s and frequent multiple-stemmed trees from the 1840’s remain as evidence of the former savanna conditions and occurrence of fire. Occasional ironwood, elm, sugar maple, and basswood occur in ravines, on hills, and on the remains of shaly limestone ridges. The richer valleys and ridges of loess and shale have better soil and support red oaks. On ridges with thin, dry soils over St. Peter sandstone abundant reproduction of white, red, and black oaks occurs. Bedrock ridges and sinkholes, perhaps collapsed limestone caves, follow the ravine bottom and are scattered throughout. Nearly 300 species of vascular plants have been observed including polypody and fragile ferns on the 6-7 foot high sandstone cliffs. Other species include blackberry, hazelnut, gray dogwood, alternate-leaved dogwood, sweet cicely, wild geranium, tick-trefoil, false solomon’s-seal, bedstraw, and lady fern. Several species of prairie plants persist on the open, sandy slopes including big blue-stem, spiderwort, shooting-star, and lead-plant. The site is home to over 40 species of breeding birds including Cooper’s hawk (Accipiter cooperii) and four state-threatened species, Acadian flycatcher (Empidonax virescens), and Kentucky (Oporornis formosus), cerulean (Dendroica cerulea), and hooded warblers (Wilsonia citrina). Olson Oak Woods is owned by the Madison Metropolitan School District and was designated a State Natural Area in 1980.