Spring Green Preserve

State Natural Area (No. 102)

Location: Sauk County. T8N-R4E, Sections 5, 6. T9N-R3E, Sections 35, 36. T9N-R4E, Sections 31, 32. 1,011 acres.

Access: From the intersection of Highways 14 and 23 north of Spring Green, go north on 23 0.5 mile, then east on Jones Road 0.75 mile (just past Fire #E5196A), then north on Angelo Lane to a parking area. Trails lead through the site.

Description: Spring Green Preserve, known as the 'Wisconsin Desert', features a rolling sand prairie on an old Wisconsin River terrace and harbors a unique flora and fauna that are adapted to the hot, droughty environment. The dry sandy soils contain many desert-like plants such as false heather, three-awn grass, prickly pear cactus, and rare prairie fame-flower (Talinum rugospermum). Nearly 40 species of annuals and biennials thrive here, a high number for a prairie, including plains snake-cotton, Venus'-looking-glass, and dwarf dandelion. Several sand blows, with shifting dunes and open sand, are scattered throughout. Bird life is diverse and includes large numbers of rare open country birds such as the dickcissel, grasshopper (Ammodramus savannarum) and lark sparrow (Chondestes grammacus). The invertebrates, however, are the most unusual of the Spring Green fauna. Several of the spiders and insects are not known from any other site in Wisconsin. Of special interest are the black widow and several wolf spiders, five species of cicada, eight species of tiger beetles, and predatory wasps. A large pocket gopher population has created patches of open ground where short-lived plants grow while the tunnels are used by many of the reserve's 10 species of snake, especially the rare bullsnake (Pituophis catanifer). Other reptiles include the six-lined racerunner and blue racer. Spring Green Reserve is owned by The Nature Conservancy and was designated a State Natural Area in 1972.