New Mexico: My dad bought property in the eighties in a very remote area in the national forest. (It was a single parcel which used to be a mining claim). The access road goes through private property and the national forest. The ownership of the property has changed and the new owner got angry at my dad and locked access to the road. So the only road leading to my dad's property which he has been using for over 40 years is now locked and we cannot access our property at all. Is this legal? And what can we do? There is no written easement. Thank you.
If there is in fact no written document (like a deed but which can also include the property sales agreement or mortgage) granting an easement to the landlocked property, I agree with adjusterjack that your dad will either have to go to court for an easement, or your dad potentially could offer to purchase the easement from the new property owner/servient estate.
Unless or until an easement is granted, the new owner of the property is within his rights to block the access road. It should be a temporary block as a court is likely to grant an easement to your dad.