Me too.Infuriating, isn't it? Had it not been for the internet, I would never have known. My parents should ask for a refund for my college education and a rebate on the property taxes they paid for K-12. I knew something of this , of course, but never heard of Gareth Jones and wasn't aware of the details.
Many of those killed were ethnic Germans who had relatives in the midwest. There were many German language papers in the Dakotas in the 1930s which published letters from the victims. The University of South Dakota translated and compiled a book of them. Article about it is here:
Pilgrims In The Valley Of Tears
NDSU has extensive archives of local German language papers from the 1880s until the 1930s. Probably many books there for someone who knows the language.