Louis L'Amour gets the award for volume (150 or so books) and perhaps should get the award for most hours of entertainment--considering how fast he must have cranked these out, they're not that bad. The style is out of date now--so much 'telling' where showing would work better, but his structure of driving the hero(s) from one looming ambush to the next makes them pretty readable. In essence, these westerns are the TV of the 1950s ('Hon, I had a long day at the office. I'm going to have a couple beers and sit on the couch with Louis L'Amour.') They were replaced by Gunsmoke, Rawhide, Have Gun Will Travel, Bonanza, The Big Valley, etc.
In a descendant's note at the end of this book, we learn that the author wrote this and other Hop Along Cassidy novels under contract to his publisher, filling in for the author who invented the character. L'Amour hated the result, having been forced (by a pile of money in the contract) to make Cassidy match the movie version of the character: truthful, fair, chaste, just, even-tempered, and generally as perfect as a saint. (Thank you, Hollywood.) L'Amour would have preferred to continue the dime-novel version of Hop Along--a rowdy, hard-drinking, brawling tough guy. We wish he had too.