"the way it used to be before ANILCA" -- for people who were actually here before that, there were no motorized vehicles on federal park lands; snow machines, airboats, three wheelers, four wheelers and the like all came much later.  No hovercraft ever.  These vehicles were rare and too expensive for the average person in the 1960s-1970s.  So prior use is just a smokescreen about 99% of the time.