The Sierra Club's official policy is that ALL trails should be closed
by default, unless each one is individually checked out, declared open,
and posted as open. After that lengthy process, they are still subject
to regular review and closure on the whim of some committee. Check the
wording for yourself he

http://www.sierraclub.org/policy/con...on/mtnbike.asp

Just how much more anti-bike could you be??