John Russell Fearn 
Valley of the Doomed [EPUB ebook] 

Rancher Calvin Wood becomes the victim of brutal outlaws who are terrorizing a remote district of Arizona. On his arrival from England, young Brad Wood undergoes a dramatic transformation when he travels to Calvin’s ranch, only to find his cattle have been stolen, and his brother’s hanged body. He changes from a feckless waster into a fighting man able to stand up to the rigours of the West. Assisted, and sometimes led by his overweight but ingenious manservant, Merridrew—who reveals sterling qualities—Brad seeks to avenge his brother’s murder and beat the mysterious raider who seems bent on destroying every ranch in Double-Peak valley…