What is the legal method of obtaining easement rights through long usage called?

The legal method of obtaining easement rights through long usage is referred to as Prescription. This concept allows an individual or entity to gain a right to use someone else's property for a specific purpose, such as access to land or a right-of-way, if they have used the property continuously and openly for a certain period defined by state law.

To establish a prescriptive easement, the usage must be apparent, continuous, and without permission (or openly sufficient to put the owner on notice), and it typically must last for a statutory period, which varies by jurisdiction. The rationale behind this legal principle is to recognize established usage that has occurred over time, thus preventing property owners from denying access when someone has been utilizing the property in a noticeable manner.

Implied easement refers to a situation where easements are not expressly defined but are inferred from the circumstances, rather than from long-term usage.

Licensing is a temporary permission to use someone else's property and does not confer property rights.

Adverse possession involves acquiring ownership of land through continuous and exclusive possession without permission for a statutory period, which does not apply directly to easements, though they share some similarities in terms of the length of use required.