I’ve been here many times — it’s one of my favorite birding spots. I stopped on the way home from Dog n Suds to do some walking and birding. Several thunderstorms were sliding through the area, so I didn’t stay as long as I wanted.
The site is notable for its kames — rounded hills that mark (if I understand things correctly) where glaciers stopped. It’s a very large conservation area, with several miles of trails including a link to the McHenry County trail that runs from the Kane County border to Wisconsin. Most of the park is prairie, but there are also several marshes, a bog and some woods.
I saw: Bobolink, Red-winged Blackbird, American Robin, Eastern Kingbird, Hairy Woodpecker, Red-bellied Woodpecker, Dickcissel, Tree Swallow, Eastern Meadowlark, American Crow, Sandhill Crane, American Goldfinch, Field Sparrow, Gray Catbird, Brown Trasher, Eastern Bluebird, Eastern Towhee, White-breasted Nuthatch, Ruby-throated Hummingbird, Indigo Bunting, Baltimore Oriole, Mourning Dove, Barn Swallow, Blue-winged Teal. I heard, but did not see, Henslow’s Sparrow, Yellow-billed Cuckoo and, amazingly, Northern Bobwhite. I also got close to a Question Mark.