Hutterite German (Hutterisch) is an Upper German dialect of the Austro-Bavarian variety of the German language, which is spoken by Hutterite communities in Canada and the United States. Hutterite is also called Tirolean, but this is an anachronism.
Hutterite is spoken in the US States of Washington, Montana, North and South Dakota, and Minnesota; and in the Canadian provinces of Alberta, Saskatchewan, and Manitoba. Its speakers belong to the Schmiedleit, Lehrerleit, and Dariusleit Hutterite groups, but there are also speakers among the older generations of Prairieleit (the descendants of those Hutterites who chose not to settle in colonies). Hutterite children who grow up in the colonies learn and speak first Hutterite German before learning English, the standard language of the surrounding areas.
Hutterite German is descended from the German which was spoken in Carinthia, in Austria, in the mid-18th century. Since the German dialects spoken in Carinthia resemble those which were spoken in the Palatinate and in Alsace (mostly Alemannic dialects), Hutterite German is fairly intelligible to a speaker of Pennsylvania German, although for geographical reasons, these two languages are rarely in contact.
It should be noted that, although at one time the Hutterites spoke Tirolean German, they no longer do. The switch among Hutterites from Tirolean German to Carinthian German occurred during years of severe persecution in Europe when Hutterite communities were devastated and survival depended on the conversion of many Austrian Protestant refugees to Hutterite Anabaptism.
Hutterite German is for the most part an unwritten language. The Hutterites employ Martin Luther's predecessor to Standard German as the written form, and every Hutterite child learns Luther's German in school (although their schooling for the most part is in English).