Apparatus, system, and method for providing an end-of-leash warning. Embodiments provide for determining when a retractable leash is about to reach a maximum state of detraction from a housing or reel mechanism as the leash is being detracted (e.g., by a dog), and generating a warning signal in response to determining when the retractable leash is about to reach the maximum state of detraction. The warning signal may be in the form of, for example, an emitted sonic signal, an emitted infrared signal, a transmitted radio frequency signal, or a mechanical vibration through the leash. The warning signal may be used to alert, for example, a dog and/or a person walking a dog that the leash is running out.