Lock 21, also known as the Yellow Bank Lock, is a notable 1830s Whitewater Canal structure built as a combined lock with rough stone walls and a double lining of tightly fitted planks to prevent water from leaking through the stone, and some of the hardware that held the wood remains visible in the walls. Locks along the Whitewater Canal were numbered consecutively from south to north, and between Brookville and Metamora are locks 19 through 25. At this point, a canal boat had to be raised eleven feet to cross the creek and reach the canal level on the other side. The Whitewater Canal Trail is presented as a path through an eleven-mile park in the Whitewater River Valley, beginning at the Laurel Feeder Dam, passing original canal locks, the historic canal town of Metamora with its working grist mill, canal boat, and covered bridge aqueduct, then continuing through open river valley scenery, past the Twin Locks, a small aqueduct at Goose Creek, habitat restoration in a canal-era ice pond basin, and relics of the old highway, with plans to complete the trail to Brookville by 2023 and two small Brookville sections already open to the public.