Greenleaf Lake State Recreation Area is a developing Minnesota state park unit in Meeker County occupying the south end of Greenleaf and Sioux Lakes and much of the peninsula between them. Its 1,230 acres preserve nearly half of the lakes’ natural shoreline and include rolling hardwood forest, wetlands, grasslands, and cropland. The area is notable for an uncommon elm-rich forest with some old-growth stands that were only lightly affected by Dutch elm disease. Good water quality and varied habitat support waterfowl, fish, and wildlife such as loons, sandhill cranes, river otters, deer, foxes, and wild turkey. Created through preservation efforts led by Mark Geyer, it remains only partly developed and still expanding.