We recently visited Robinson Falls (aka "Corkscrew Falls") at Boch Hollow State Nature Preserve. The waterfall is located off-trail at the preserve, so we obtained a free permit from the Ohio Department of Natural Resources to visit the falls. Along with the permit, they sent us a map showing the falls, where to park, directions, and preserve rules.
The ODNR-provided map directed us to a small pull-off from the road that holds a couple of cars. We located the trail-head across the Read more ➜ Boch Hollow State Nature Preserve: Robinson Falls
We recently visited Robinson Falls (aka "Corkscrew Falls") at Boch Hollow State Nature Preserve. The waterfall is located off-trail at the preserve, so we obtained a free permit from the Ohio Department of Natural Resources to visit the falls. Along with the permit, they sent us a map showing the falls, where to park, directions, and preserve rules.
The ODNR-provided map directed us to a small pull-off from the road that holds a couple of cars. We located the trail-head across the Read more ➜ 
We visited Boch Hollow Nature Preserve again last week. The weather was just about perfect. Here's a few pictures from our hike.
This opossum was slowly wondering up a dry stream bed when he decided to stop and pose for a picture.
Additional information
TrekOhio: Hocking County Parks & Preserves — This is the county where Boch Hollow is located; check out this page for links to the official site and for information 
The parks and preserves in the Hocking Hills area are great destinations for the outdoor enthusiast. We've hiked them all - Hocking State Park, Conkle's Hollow, Rock Bridge, Wahkeena, Boch Hollow. Wait ... Boch Hollow?
Boch Hollow is a 570 acre preserve located north of Logan, Ohio. Like Rhododendron Cove and Christmas Rocks, Boch Hollow used to be a permit only preserve, but it is now open to the public. We've provided directions to the preserve at the end of this article.
Boch 
Here's several photos from the area around Boch Hollow. They were taken September 29th, 2012.
Boch Hollow is a State Nature Preserve in Hocking County, a bit south of central Ohio.