Jackson Falls

Jackson Falls is one of only two waterfalls on the 444 miles of the Natchez Trace Parkway, and it exists because a river stole a creek. Jackson Branch is about 1.3 miles long and dry for part of the year, and for thousands of years it ran along a high valley cut off from the Duck River below. The Duck ate back into the bluffs until it captured the branch, and the water now abandons its old course and drops into the Duck valley over Ordovician limestone of the Nashville Group. The Park Service calls it a classic case of stream piracy. A concrete path 900 feet long runs down to the pool at the foot.

The drop comes in two steps, and the rock is why. The mapped contact between the Bigby limestone and the Hermitage Formation beneath it, thin-bedded with shale partings, falls midway down the cascade. The Park Service publishes no height for this fall, though it gives one for Fall Hollow further south. Lidar profiles of the channel give roughly sixty feet for the pair of steps, and the pool sits about 110 feet below the parking area above.

Baker Bluff and Delk Bluff flank the falls on the outer wall of Greenfield Bend, a great meander of the Duck. The branch reaches the river a few hundred feet downstream, and the Duck runs on north to the parkway bridge about four river miles downstream, the lowest ground the road crosses in Tennessee, at about 500 feet. The Park Service's 2014 assessment counted the falls among three water-quality stations it sampled regularly in the Lower Duck watershed.