Re: BK. Kid Blackie
I live in Colorado and was fortunate enough to find this book at my local library (I'm guessing it doesn't have too wide a distribution across the country) and enjoyed it when I read it several years ago. It isn't particularly well-written but the author, Toby Smith, did some good legwork in collecting details from this era in Dempsey's life, focusing on the Colorado mining towns where the itinerant worker Dempsey would have migrated for jobs. From the tiny town of Ourey (a very pretty place and a primo locale for off-road bike, motorcycle, and RV trails, BTW) Smith tracked down a 1916 receipt signed by Dempsey for the rental of a mule. At least a couple of Dempsey's "officially recognized" bouts entered the cannon due to Smith's research, and some of the first-hand recollections from local codgers are interesting.
If you come across a copy (and I see the major online booksellers have it for under $10) I think you'd probably find it a worthwhile read.