I would have included boundary by acquiescence if this OP was not in CA. In 2012, CA court of appeals decided a case that effectively struck down the doctrine unless there was an agreement between neighbors. California courts will not apply the agreed-boundary doctrine to resolve property boundary disputes when there is no evidence that neighboring property owners entered into an agreement to resolve a boundary dispute and the true boundary line can be determined from the legal description in an existing deed or by a survey.

