Here's what I found on the web:
EASEMENTS
An easement is a non-possessory interest in land owned by someone else which entitles the owner of the interest to a limited use or enjoyment of the land and to protection from interference with its use.
Because an easement is an interest in land owned by another person, it must be transferred and used subject to laws governing real property. A land owner cannot, as a rule, have an easement over his own property. An easement holder is not entitled to the same benefits as a person who has rights of possession, such as a tenant under a lease.
The most common easements are access easements, which grant the right to cross someone else’s property on a designated road. Another type is a solar easement, which would, for example, grant the easement holder permission to come on neighboring property and trim landscaping above a certain height to prevent it from blocking solar panels.
Easements can be divided into two classes: easements appurtenants and easements in gross. “Appurtenant” means “belonging to,” and an easement appurtenant is created for the benefit of and belongs to another tract of land. In a roadway easement, for example, parcel A would grant an easement to parcel B for access to a public road. That easement would “burden” parcel A and “benefit” parcel B, regardless of who owns the property.
An easement in gross is a personal right in another person’s land. Such easements could be granted to utility companies to install and maintain telephone lines on private property.
Unless otherwise specified in the easement document or by subsequent amendment or termination, the term is perpetual. Once an easement appurtenant is granted, it runs forever with the land for the benefit of the “dominant tenement,” or the tract of land to which the easement belongs. Easements in gross also continue in perpetuity no matter how often the property changes hands. In both cases, renegotiation is necessary only if all parties agree to it.
If the easement is granted by someone other than the fee title owner, however, it’s valid only for the duration of that person’s estate in the property. For example, an easement granted by a tenant under a 10-year lease would terminate with the lease.
Easements can also be terminated when they no longer serve the purpose for which they were granted, by merger of the two tracts of land involved in the easement, by foreclosure or by an owner releasing or abandoning his interest in the easement.
The deed holder has full rights of possession and enjoyment of the property. He may grant the easement to other parties, sell the land over which the easement runs, plant shrubs and crops or erect fences, as long as it doesn’t interfere with the easement holder’s rights.
The easement holder only can use the land for a stated purpose, such as access to a road or a water line. He does not have a possessory interest in the property so he can’t restrict use or possession by others, as long as that use doesn’t interfere with his use or enjoyment of the easement. Nor can the easement be granted to a third party.
Maintenance obligations are typically outlined in the easement document. In the absence of specific provisions in access easements, Oregon Law has determined that each party shall be responsible for maintenance costs in proportion to their use of the easement.
To protect the rights of the easement holder and property owner, put any oral agreement in writing and record it in the county in which the property is located. Be specific about the terms of the easement. If you’re granting an easement for a road and don’t want logging trucks or long haulers using it, be sure to set forth this exclusion in the easement document. If you’re purchasing an easement for your own access and you expect it to be used for several parcels you’ll partition from an existing parcel, make sure the grantor of the easement agrees to this, or your development plans may suffer.
Also, be sure to include the legal descriptions of both easement and property to be benefited by it. Unlike other real property, an easement can be considered valid without a locatable legal description, but an easement “over the existing roadway” may adversely affect your property should there be a dispute over the location.
Finally, consult a real estate attorney, surveyor and/or title insurance company for help drafting the legal description and terms of the easement.