The Marietta and Cincinnati Railroad, built in the mid-1800s, ran across southern Ohio between its two namesake cities. The line was absorbed into the Baltimore and Ohio Railroad as its Southwestern Division, then merged into the Chessie System in the 1970s, then into CSX Transportation. When CSX abandoned the segment through the Zaleski State Forest in the late 1980s, the right-of-way could have been sold piecemeal and lost. Instead, Athens and Vinton County commissioners acquired the abandoned grade using Clean Ohio Conservation Fund grants. Track went out. Trail came in. The corridor passed from one form of public transportation to another.

The trail's most distinctive features are its two tunnels, each from a different era of railroad construction. The Moonville Tunnel is the famous one, a stone-and-brick masonry passage in Vinton County that lent its name to the ghost town it once served and which still draws thousands of visitors a year for the legends attached to it. The King's Hollow Tunnel in Athens County is structurally rarer - a timber tunnel, with wooden support framing rather than masonry. Timber tunnels were cheaper to build but harder to maintain, and most have disappeared from American rail lines. The King's Hollow Tunnel survives largely because the railroad abandoned it before time and weather had finished their work.

Rail-trails often inherit the bridges of the railroads that preceded them, but the M&C corridor presented a problem: the dismantling crews removed many of the railroad bridges along with the track. The trail surface is gravel and dirt, and many of the stream crossings now require improvised fords or detours. The Moonville Rail-Trail nonprofit has been working since the 2000s to rebuild bridges that allow continuous passage. A new Raccoon Creek bridge funded in 2020 marked an important step toward a complete through-route. Until all the gaps are bridged, hikers and cyclists handle the stream crossings the way the locals always did - by hopping rocks or wading.

The current rail-trail runs from Zaleski on the west end to Mineral on the east, but the long-term ambition reaches farther. The west end could eventually link toward Chillicothe, where M&C track remains intact. The east end could extend toward New Marshfield and then to Athens, where it would meet the Hockhocking Adena Bikeway. A complete southeast Ohio rail-trail network would link Wayne National Forest to multiple state parks, river towns, and the campus of Ohio University. For now, the Moonville Rail-Trail is a ten-mile sample of what the network could be - and a way to walk into the Moonville Tunnel on a fall afternoon without having to climb over a chain-link fence.