Fall Mountain Slide (also known as The Remnants of a Lost Leaf Track) is a custom track created by SlipperyMac. The race occurs on wide-open and dangerous terrain that remains barren after the surrounding scenery was stolen by the Koopalings. According to the author, the race's unique concept and simplistic visuals are a result of time constraints. The author worked on the scenery during the last day of production and believed the visuals he worked towards could not be achieved in such a short time span. He opted instead to give the track a deserted and risky feel to fit the deadline, though he states that the intended visuals will return in future updates. The track was completed in four days as part of BillyNoodles's second-ever Custom Track Jam, where it placed second.