In Western Coal & Mining Co. v. Jones (1946) 27 Cal.2d 819, the California Supreme Court held that a sister state judgment entered on the ground that the statute of limitations has run on an obligation is not res judicata in this state if not barred by California's statute of limitations. (27 Cal.2d at p. 827.) As the court noted, "the general rule is that the running of the statutory period does not extinguish the cause of action, but merely bars the remedy. That is the law in California. The law of the forum rather than where the obligation arose governs statutes of limitation and their applicability," except in circumstances not here pertinent. ( Id. at p. 828.) In other words, a statute of limitations bar is a procedural, rather than substantive, matter. (3 Witkin, Cal. Procedure, supra, Actions, 103, p. 168.) A sister state judgment rendered on that ground consequently is not a determination on the merits in California. (Western Coal & Mining Co., supra, at p. 828.) It has no res judicata effect for that reason.