American Coaster Enthusiasts (ACE) recognizes Kennywood's Jack Rabbit as an ACE Roller Coaster Landmark, a designation reserved for rides of historic significance. Featuring four drops into a natural ravine, Jack Rabbit is best known for it signature airtime-producing, 68-foot, 6-inch "double dip" following an uncommon mid-course lift hill. The 2,132-foot long wood coaster was constructed in 1920 by the fabled "Golden Age" coaster design team of John Miller (1872-1941) and Harry Baker (1887-1939), at a cost of $50,000, with construction supervised by Kennywood's Charles J. Mach. It was the park's first coaster feature Miller's patented and revolutionary underfriction wheels, which locked the train to the track, allowing for steeper and more daring drops than previously possible. When it first opened to the public on June 18, 1920, Jack Rabbit featured a dark tunnel around the lower back turn that was removed during the 1940s, but was later reinstated prior to the 1991 season. Noted also for its classic Edward Vettel Sr.-designed trains with stationary lap-bars that replaced the original open-front trains in 1951, Jack Rabbit has remained one of Kennywood's most popular coasters for over 90 years. As one of the oldest operating coasters in the world, Jack Rabbit is a true classic from another era and a longtime Pittsburgh-area institution. ACE salutes Kennywood, a National Historic Landmark, for continuing to operate and preserve Jack Rabbit for generations of riders to enjoy.