There are tons of questions to go along with your story.
Most end up creating hypothetical situations (guesses at best)
Someone got upset and took out a couple bridges.
Was it was really anti-MTB, or just anti-people coming into an area where they never were?
who knows?
Sure they could have just reached out, or posted some signs - but it was probably building up to something like this.
Unfortunate.
We'll live with it - try to be the best co-users we can be, and hopefully show that by our actions,
specifically like you mentioned, being aware of when hunters are expected there.
strangely enough, mtb is an acceptable method of transportation for hunters.
I'd even like to put forward that ebikes would be a great alternative, and should be allowed.
And i'm still not thinking it is hunter specific - so i don't want to seem that way.
Really hard to get upset at someone that got so angry that they felt they had no other recourse.
What I was really upset about was the apparent booby-trapping of one of the bridges - possibility of collapse
while being used. It is so random, that it might have been any kid just having fun, not more than 50' away from
a fire station with a banquet room.