John Wood Clay & Clarence E. Mulford 
Buck Peters, Ranchman [PDF ebook] 
Being the Story of What Happened When Buck Peters, Hopalong Cassidy, and Their Bar-20 Associates Went to Montana

The beloved Hopalong Cassidy series takes a dark turn in this grim but gripping Western novel from Clarence E. Mulford. Buck Peters sets out for Montana to make a fresh start as the part owner of a ranch, but when he arrives, he finds that his property has been ravaged by hostile neighbors. At the end of his rope, Peters decides to call on his old friend Hopalong Cassidy to help win back what is rightfully his.