I was in a horse group that is doing the same thing now. They used to be inclusive working with all groups to keep trails open. The group has been taken over by that same mentality of close off all others except themselves by backing the closing of Forest Service roads. Sierra club foot prints there too.
They stopped sending me membership renewals when I voiced opposition to the closures. Years before I remember another person removed from the membership because of voicing opposition to government closures of BLM & Forest Service lands. We were both officers of the organization at one time. Lots of volunteer hours etc.
Same song, different dance. And people never learn. Infiltration is the hallmark of the leftists. It’s what they do and why they win.
And people just go along so as not to offend. That was why I stopped. Got sick of fighting my own team.