Most easements are assignable. Some are not. Assignable means the easement can be sold, gifted, devised, inherited, or otherwise conveyed. Rules concerning assignability of easements depend on several factors, the major factor being whether the easement is an easement in gross or appurtenant.
Easements appurtenant run with the land: Whoever possesses the dominant estate (by purchase, gift, devise, or inheritance) has the right to use the easement over the servient estate. A person conveying the dominant estate loses her easement rights to the person to whom it is conveyed. Likewise, the servient estate remains burdened with the easement no matter who owns the servient estate. Moreover, an easement appurtenant is implicitly assigned with the dominant estate, whether or not the deed mentions it.
An easement in gross benefits a person whether or not he owns a particular parcel of land. It lacks a dominant estate. The rules relating to the assignability of easements in gross are evolving separately for commercial easements in gross and for noncommercial, or personal, easements in gross. Commercial easements in gross further a money-making activity. Noncommercial or personal easements in gross are granted for the owner's personal enjoyment or pleasure. Railroad, utility, and pipeline easements are commercial easements in gross. A commercial easement in gross also might be the right to use a lake to run a fishing, boating, or swimming operation, or the right to remove timber or minerals from the land (the latter being profits a prendre or profit—and profits are everywhere assignable).