Milwaukee's Bock Bier festivals; a lost tradition?

You don't hear about an annual Bock Beer season in Milwaukee, although one celebration has apparently taken place for 38 years on the last Saturday of April for ... 38 years! (I'm not a beer drinker, so've never followed the event.)
It used to be that every tavern in town placed advertisements in the local German papers for their brew in late winter and into early spring. This advertisement for Best's Bierhalle special goat-brew dates from the 1850s.

More information can be found at: http://en.wikipedia.org/wiki/Bock
https://shepherdexpress.com/events/bockbierfest-2018-38th-annual/