[pct-l] Trail clearing with horses and chainsaws

[Devon Taig]

As I was walking across Oregon this year, I ran across a trail maintenance
group (I think from the PCTA) near Three Fingered Jack.  They didn't have
horses or chainsaws and were facing the daunting task of clearing dozens of
trees using handsaws that had apparently fallen during a wind storm the
previous winter.  When I inquired why they weren't using horses and
chainsaws, I was surprised to hear that they were banned on that part of
the trail.
I'm not clear as to why such a ban would exist in the context of people who
are actively performing trail maintenance.  It would seem to be at least an
order of magnitude easier to clear a trail with a chain saw and a horse
than by hand.  I would like to think that when I donate to organizations
that do trail work that they aren't hamstrung by federal bureaucracy that
impedes getting important work done.  Can anyone shed some light on this?

Devon