i interpreted it as they could build trails without permission from natural resources - since they had to mark them equestrian safe, etc. they just exclude certain activities in there - one being mountain biking.
Nobody is acting in bad faith - nobody is going to read the deed in 2010, because nobody would question passive activities.
i'll now update what i think happened (meaning speculate.) Since it has specific references to equestrian activity, mountain bikes were excluded,
because just down the road, not too many years before, whole counties and parks were excluding mtb cause of a few
that would buzz past horses and people.
Doesn't seem unreasonable. We now have an ally who may choose to pursue a change.
If not, we should not act entitled. There was no malice. We'll hook up the field trail from across the road, and move on.