An update: the last seven miles on Monday were very difficult, sort of like the Ohio equivalent of the Himalayas. The biggest problem on the backpacking trip was that the big 15-mile loop had not been maintained at all this year (and maybe not for a few years). The inner 5-mile loop was cleared and made for easy trekking. But the outer loop was overgrown and clogged with treefalls--it was basically a game trail. By about Mile 10 on Monday, I was really tired of the downed trees. Every extra step, every maneuver over a log, duck under branches, dodging of thorns, took a huge effort. On two of the worst tangles, we were forced to take off our packs and crawl.
Thankfully, it was relatively mild (low 80s) and rain-free. The cold beverage at the end of the trail was worth the wait, as was the clandestine shower at the nearest state park campground. I'm looking forward to some time here in the park in Chicago and future backpack trips on short, wide trails.