A homeowner obtained the permanent right to pass over a neighbor's land to access a river. What is this legal right called?

The legal right that allows a homeowner to pass over a neighbor's land to access a river is called an easement. An easement is a property right that grants an individual or entity the authority to use a portion of another person's property for a specific purpose, such as access to a waterway. This right is typically permanent and can be created through a written agreement, necessity, or long-term use, making it a vital aspect of property law.

In this scenario, the homeowner's right to pass over the neighbor's land is not merely temporary or informal but is instead a recognized legal entitlement. This distinguishes an easement from a license, which is generally revocable and does not grant any lasting rights. Additionally, the concept of a right of first refusal pertains to an option to purchase property rather than the use of another's land, while encroachment refers to a situation where one property owner unlawfully extends their property into the boundaries of another, which does not apply here.