Winter in Spring Green Preserve

Formed roughly 17,000 years ago when glacial Lake Wisconsin burst through its embankments and left sandy soil in its wake, the Spring Green Preserve — or Wisconsin Desert — is a 1,300-acre parcel managed by the Nature Conservancy since 1971.This unique State Natural Area transforms into a serene, monochromatic landscape in winter, where dormant prickly pear cacti — the preserve’s signature species — wait beneath the frost. While summer brings scorching ground temperatures of 120 degrees, the winter months highlight the preserve’s rare geology. The 1.6-mile trail, cutting through a mix of sand prairie and black oak barrens, leads hikers toward the towering dolomite bluffs. From there, hikers can take in a stunning view of the Wisconsin River Valley. (Photo by Mike Marquardt)