Some of these are paywalled but I don't see where the ones that aren't support the claim re: hiking that "...any attempt to organize around it without making overt, aggressive attempts to include minorities is a sign of white supremacy"

Observing that, say, parks are being patronized by certain demographics is far from condemning those parkgoers as white supremacist.

The only bits you link about white supremacy seem to be about climate change which has a whole different angle (marginalized communities being first in line for ill effects in many areas) and isn't particularly relevant to the original claim here.