Why aren't Riverbench sparkling wines “Champagne?”

Since 2005, only wines grown and produced in the Champagne region of France can be legally called “champagne”. Because we grow and produce wines from California's Central Coast in the United States, we do not label our bubbly as Riverbench champagne but rather as Riverbench sparkling wine made in the Méthode Champenoise. This indicates that we follow the same processes as traditional French champagnes and use only the three traditional noble grapes: Chardonnay, Pinot Noir, and Pinot Meunier.