I started researching the Arizona Territorial Prison in Yuma, while writing a story about the so-called Gates Riot (actually an attempted escape which resulted in the deaths of four inmates) at that place. As is my research routine, I began collecting all the secondary sources I could about this institution. I was surprised to find there are only about six, and not one of them is over 200 pages in length. Most of these, including Adobe and Iron by John Mason Jeffery, and The Hell Hole by William and Milarde Brent, seem as though they were written specifically to be sold through the gift shop at the prison park (the Territorial Prison became a Arizona State Park in 1961). In further research, I did find two manuscripts of more substantial length - one, a Masters thesis by Don Malone, dating to 1969, and the other, a collection of documents compiled by William Haught, dating to 1971. I should also mention Gates of the HellHole, a biography of Superintendent Thomas Gates, by Carole Gates Sorensen, but this only covers a brief period in the existence of the penitentiary. However, these few books are the extent of the extant secondary sources about the place. Guess I know what my next manuscript will be about. The dearth of literature is rather remarkable, being this particular institution is so (in)famous (remember 3:10 to Yuma?), but then again, there is a lot of Arizona territorial history which has yet to be thoroughly researched and shared.