What Does van Gogh's Ear Have to Do With Gold Rush California?

What does van Gogh's ear have to do with gold rush era San Francisco? Not a thing it seems, other than this typo in the headline and the display of one of van Gogh's works.

I think the typo is "Gold Rush-ear" which should have read "Gold Rush-era" - and being easily confused as I sometimes am, my mind tried to put "gold rush" "ear" and "van Gogh" all together in the same thought.

So when I started to read the actual article, it made no sense! Is it just me? Is this some odd form of dyslexia? Early dementia?