Ezra Pound, native Idahoan and celebrated poet, who followed the slippery slope of socialism into full-on fascism, became a sycophant of Hitler and Mussolini, and eventually stood trial in the US for treason.
Lyda Shaw, Idaho's most notorious serial killer, whose marry-and-bury modus operandi enabled her to make a literal killing on her late husbands' life insurance policies.
Caleb Lyon, the second territorial governor of Idaho, who used his social prominence and political connections to make a very comfortable living (sometimes shored up with his own embezzled funds), dodging any of the actual duties that came with his political appointments, and doing precious little else.