Bayrisch is the Bavarian dialect and the BBC had an article this week about an Englishman who is compiling a dictionary of Bavarian words and phrases.
Griàss aich, laidl, gfraid me, dass hergfundn habts is the welcoming sentence on this Bavarian website. Quite different from the standard German Grüsst Euch ... es freut mich, dass ihr uns gefunden habt (I don't know what laidl is, Leute perhaps). So that gives you an idea of the work involved in creating a dictionary. It won't be finished until 2050, apparently, and is expected to be between eight and ten volumes long.
Bavaria had its own king until 1918, and many Bavarians still feel very different from other Germans. You often see people, even young people, wearing dirndls (women) and lederhose (men) and the dialect itself is enjoying something of a renaissance.
Thanks to Elizabeth for sending me the link.