A prescriptive easement—also known as an easement by prescription or an adverse easement—is an easement (right to use property) created by a use of property (the servient estate) that is open, continuous, and adverse to the owner of the property (the servient estate).

To satisfy the requirement that the use be continuous, the use must take place over a required period of time—which may be specified in a state’s court opinions (common law or case law) or in its statutes if the state legislature has written the law regarding easements into statutes or code. If the state legislature has written a law in statutes or codes the law is said to be codified.

In Colorado, a prescriptive easement is established when an individual uses another's property in a manner that is open, notorious, continuous, hostile, and under a claim of right for an uninterrupted period of 18 years. This is codified in Colorado Revised Statutes under section 38-41-101 et seq. The use must be such that it gives the owner a reasonable opportunity to notice that someone is asserting a right against their property and must be without the owner's permission. If these conditions are met, the user may be able to claim a prescriptive easement, giving them the right to continue using the property in the established manner. It is important to note that the specifics of each situation can be complex, and the advice of an attorney may be necessary to navigate the legal intricacies of establishing or disputing a prescriptive easement in Colorado.