The field in front of you (south) was cropland until the 1950's and behind you (north) until the early 1970's.  About 80% of Illinois is now in agricultural use (crops, pastures, orchards, etc.), but before the pioneers began to change things, 60% of the state was prairie.  Today, less than 1% prairie remains!  The Winnebago County Forest Preserve District is attempting to "turn back the clock" here, to give you a glimpse of what Northern Illinois was like until about 150 years ago.  Restoring agricultural land to a more natural, native community is painstakingly slow, but eventually most of the plants that used to live here will be reintroduced.