From Maison-Champagne.com website:
"By a law passed in 1927, the Champagne production zone (AOC vineyard area) is a defined area of 34, 000 hectares. It is located in France some 150 kilometres to the east of Paris and spreads across 319 crus (villages or communes) in four main growing areas: the Montagne de Reims, the Vallée de la Marne, the Côte des Blancs and the Côte des Bar.
Together these comprise 281,000 plots of vines, each measuring roughly 12 ares (100 square metres). Seventeen villages rank as Grand Cru and 44 as Premier Cru. The vineyards are planted at altitudes of 90-300 metres, on predominantly south-, southeast- and east-facing slopes (coteaux) with an average gradient of 12% (up to 60% in some places). This undulating to moderately steep terrain creates ideal vineyard sites, combing optimum exposure to the sun with good natural drainage that prevents soil saturation."
Download pdf info packet (French only, sorry).
Dividing the Geographical areas:
The four main growing areas: the Montagne de Reims, the Vallée de la Marne, the Côte des Blancs and the Côte des Bar with their subregions.
Montagne de Reims
Grand Montange de Reims
Massif de St Thierry
Monts de Berru
Reims: Vesle & Arde
The Marne Valley
Côteaux Sud d'Epernay
Grande Vallée de Marne
Terroir de Condé
Vallée de la Marne Ouest
Vallée de la Marne Rive Droîte
Vallée de la Marne Rive Gauche
Côte de Blancs
Côte de Blancs
Montgueux
Sézannais
Val du Petit Morin
Vitryat
The Côte des Bars
Bar sur Aubois
Barséguanais