Data for the different regions taken from "Köbler, Gerhard, Althochdeutsches Wörterbuch, (4. Auflage) 1993"; See also: Oldhighgerman Dictionary - University of Innsbruck (german)

All 5 indicated West Germanic language variants have undisputed documents and primary sources. Old Thuringian has no undisputed primary sources and is hence not indicated on the map, but marked as Franconian. Lombardic and Old English aren't indicated either.

Caption in Standard German says the following (from top to bottom):

• Old Franconian (Rhine, Mosel, Central and Low Franconian)
• Old Alemannic
• Old Bavarian
• Old Saxon
• Old Frisian (should not be included on the map)

Borders: Mind that the borders drawn on this map are only approximate. Not enough data has been handed down from the Early Medieval Period to guarantee 100% accuracy for any historic conclusion.

Undisputed primary sources before the year 1000 are, e.g. for:

• Old Franconian: Augsburger Gebet, Fuldaer Berichte, Fränkisches Taufgelöbnis, Hammelburger Markbeschreibung, Kölner Taufgelöbnis, Lex Rivaria, Lorscher Bienensegen, Mainzer Beichte, Merseburger Gebetsbruchstücke, Pfälzer Beichte, Pariser Tatianfragmente, Reichenauer Beichte, Rheinfränkische Cantica, Trierer Capitulare, Trierer Verse wider den Teufel, Würzburger Beichte, Weißenburger Katechismus, Würzburger Markbeschreibung.
• Old Alemannic: Alemannische Psalmenübersetzung, Benediktinerregel, St. Galler Schularbeit (Brief Ruodperts), St. Galler Schreibvers, St. Galler Sprichwörter, St. Galler Spottverse, Notker, Notker Glossator, Otfrid of Weissenburg, Physiologus, Weingartner Buchunterschrift.
• Old Bavarian: Altbayrische Beichte, Bruchstücke einer Beiche (Vorauer Beichte), Altbayrisches Gebet, Carmen ad Deum, Exhortatio ad plebem christianam, Freisinger Paternoster, Hildebrandslied, Jüngere Bayrische Beichte (1000), Kassel Conversations, Mondseer Fragmente (Vienna fragments), Freisinger Petruslied, Pro Nessia, Psalm 138, Sigharts Gebet, Wessobrunn Prayer, Wiener Hundesegen, Abrogans (disputed), Muspilli (disputed)
• Old Saxon: Sächsische Psalmenbruchstücke, (De Henrico), (Hildebrandslied)