We own 20 acres in Washington State. This is rural property with a
small cabin that sits right off of a private easement road that runs
through our property. There is a very clearly documented
ingress/egress/utilities easement for specific parcel owners to use
this road. Basically, it allows specific parcel owners to cross
through neighboring property to get to their own. All easements end at
our property.

There are 5-6 properties beyond us that have no easement to cross our
property. Their property can be accessed from the other direction
through a Forest Service Road that runs through their property. This
forest service road has an easement for anyone to come across it.

We have no issue with those who have an easement crossing our
property. Although we are the last parcel on the easement some of the
owners come across to access the Forest Service road and forest
service land just beyond our property.

However, we wish avoid any future claims against our title for
prescriptive or other forced easements from people who do not have a
legal right to cross but just assume they can. At this time, we do not
believe there is a history of consistent use that would allow this type
of easement to anyone.  

QUESTION:

We plan to own this land for many years to come. Is there anything we
can do now to protect our property rights from future claims and keep
people from using/trespassing on our private road when there is another access road?

You can close off access to the road one day a year to prevent them
from creating an easement.

Post signs that the road is for authorized users only.

If yours is the last house on the road and it is a private road get
permission to construct a gate so no one can go past your house. 
Authorized users would be provided a key or combination to open the
gate.