Yes, this is true. Cascadian Dark Ale still sounds idiotic to me and with a bit of arrogance, with the claim of the Northwest originating the idea of a hoppy dark ale. Shenanigans! FWIW, I've never heard a NW brewer claim to have invented it or claim that it was invented in the NW. But there's a lot of them here, it seems like every brewery makes one. I assume that's where it came from. Bouef.
But I'd still take CDA over Black IPA, that is even more foolish.
From the articles & beer blogs that I've read, it seems like a NW beer writer, Abram Goldman-Armstrong, is the one who's championing the name CDA and the idea that the style was a NW creation He cites John Maier's Skull Splitter as being the seminal beer & The 2003 Oregon Brewers Fest being the time & place it was introduced. The brewers may or may not be claiming to have invented the style, but NW beer writers certainly are. I know that Greg Noonan was brewing his Blackwatch IPA in the mid-90's. I had the opportunity to try it when he brought some of that beer to the Sunshine Challenge in Orlando where he was a guest speaker on Strong Scotch Ales.
However, the black ipa 'style' goes back waaay before that. Check out this passage from the 1888 book - "The Theory and Practice of Modern Brewing" by Frank Faulkner, 1888, pages 259-260. I guess 'modern' must be a moving target
The key part is the last sentence or two where he talks about it being a variant of the Burton ales (hoppy pale ales & IPA's). Anyway, thought it was an interesting reference that shows this certainly isn't a new style. It may be popular in the NW, but certainly didn't start there. Here's the passage......
"The varying classes of black beer are produced in several distinct centres of brewing by as many different methods, but, as a rule, we have two main principles in operation—the use of a soft water in conjunction with malt of distinctly heavy character, not inefficiently grown, but at the same time not by necessity so fully vegetated as that employed in the production of pale or stock beers.
The possibility of using such material turns upon the fact that a large proportion of the malt used consists of highly caramelised varieties, and, as before explained, caramelised bodies possess a marked preservative or antiseptic character, while the black beers produced are not always required to keep for any very lengthy period. To begin with, then, it is not customary to employ saline waters, or, in other words, if such water be employed the black beer produced is deficient in that roundness and fulness of palate taste that is considered so necessary a feature, while I can example this by referring to the black beer produced at Burton, which has been universally described as a mere black pale ale—i.e., though black in colour, its palate taste reminds one very strongly of the pale beers produced by Burton firms. It will be quite understood that I am not decrying this article; it may and does suit many palate tastes, and is thought a great deal of on the Continent, but at the same time it differs very widely from the accepted standard quality of a black beer as specified."