An easement is an interest in land that is owned by another person and gives the easement holder or easement owner the right to use or control the other person’s land in some limited way—such as the right to drive across another person’s private property to access a public highway or other public road (an ingress-and-egress easement).

There are many different types of easements, depending on the nature of the use of the land—such light-and-air easements; mineral easements; timber easements; noise easements; and railroad easements—and how the easement was acquired—an express easement; an implied easement; a prescriptive easement; an easement by necessity; or an easement by estoppel, for example.

There are also negative easements that prohibit the owner of a property (the servient-estate) from doing something, such as building a home or structure that blocks the view or sunlight for an easement holder—often an adjoining property owner (the dominant estate).

Public utility companies (gas, electricity, telephone, water, sewer, cable, etc.) often have easements to place utility transmission, distribution, or power lines on private property and access them for installation, repair, and maintenance.

Laws regarding easements vary from state to state and may be located in a state’s court opinions (also known as its common law or case law) or in its statutes.

In Montana, easements are recognized as non-possessory interests in real property that allow the holder to use land owned by someone else for a specific purpose. Types of easements in Montana include, but are not limited to, ingress and egress easements, utility easements, and negative easements. Easements can be created in several ways: expressly through written agreements, by implication, by prescription (similar to adverse possession), by necessity when landlocked property requires access, or by estoppel, which prevents the landowner from denying access if certain conditions are met. Montana law also recognizes conservation easements, which are voluntary legal agreements that permanently limit uses of the land to protect its conservation values. The specifics of creating, transferring, and terminating easements, as well as the rights and obligations of the easement holder and the property owner, are governed by Montana statutes and case law. Public utility companies often have statutory easements for the purpose of installing and maintaining their infrastructure. Disputes over easements may be resolved in Montana's courts, where judges interpret the scope and extent of easements based on the state's common law and statutory provisions.