That's very interesting. Using Google Earth, which gives you approximately the past 20 years of satellite imagery, it appears it was not there in 2002, but may be there in 2005. Even when it was there, it looks like it went straight and dead ended behind the house at the end of Flint Creek Drive. 2p008 has a really clear shot that shows there is no turn table on the north end. Then in 2009, there's a low-quality image that appears to be churned up dirt, and it's not until 2013 where a high-quality image is finally posted and the northern turntable is clearly evident.
This reminds me of the miniature railroad in Richmond, IL at the intersection of Hill Road and US-12. It appears to be gone now, but the ROW is still visible. Again, if you have Google Earth, check it out in 2013 and 2003, you get great views of it, including a trestle over the local creek. If I see that path correctly, it was 2.5 miles of track. The land is for sale, so I wonder if they pulled it up and moved it, sold it, or scrapped it. I want to say the store at the cornet of Hill and 12 was a Lionel store, which would make sense, but I haven't been able to find any info on it.
While researching that Richmond trackage, I came across this forum thread that lists a whole bunch of miniature railroads, including several others in Illinois:
http://cs.trains.com/trn/f/111/t/80897.aspx