trail preservation...have a question

["superpat" <superpat@gateway.net>]

Hi All,
About four years ago at AERC convention, I sat in on a trail preservation
meeting and heard a speaker who has worked for years on developing and
preserving trails.
She pointed out that when a trail has been used for a number of years (is
there a specific amount of time?) even if it is on private land, access
cannot be denied. (kind of like a grandfather clause?)
I am currently working with a consortium of community members and various
trail users, the Forest Service and City Park Commission to build and
renovate and maintain trails in our area. In one area, a portion of a trail
goes through three plots of privately owned land. One of the land owners is
working with the consortium but we have been unsuccessful in contacting the
other land owners. As we devise a plan for re-routing the trail, it will
still be necessary to go through a small portion of some of the private
land. It would be helpful to know if what I remember hearing is correct.
Does anyone out there know if and where I can find information about the
necessity for private land owners to allow access to trail when the trail
has been in use for a number of years?
Thanks for any help or suggestions.
Pat Super