Unfortunately I have been down this "track"  before with suggestions and discussions that came to nothing.  After a month of going nowhere with any of the platforms (including OSM) it was decided to simply delete them before they propagated.  In this instance the lines do not seem to propagate to AllTrails, but they do show up on Strava and are used by "enthusiasts" to generate segments.  
Strava have a code of conduct in this regard that they ignore and do nothing to delete these segments even though they know them to be illegal.  AllTrails will delete features if they find them to be illegal.

The user that generated this tracks is a mountain bike enthusiast that is known to the Parks department who have tried discussion in the past as well.

From the point of view of the Parks department they are the only authority that the right to generate (and maintain) trails through the National Parks.  After all, they know where the areas of danger are, and where the endangered species live.

If people want specific routes in National parks OSM need a find way of isolating National Parks and giving administration rights to  the Parks department for these areas.  They do not mind people suggesting tracks, what they do not like is wasting time, monitoring OSM and other platforms, attempting to have them erased on all the platforms and putting notices up in the park blocking the illegal tracks.