Dierkes was born on February 10, 1905 inCincinnati, Ohio. He attendedBrown Universityand subsequently went to work as aneconomistfor theUnited States Department of State. In 1941 he joined theRed Crossand served in theBritainduringWorld War II. There he met directorJohn Hustonwho recommended that he tryHollywoodafter the war. Instead, Dierkes went to work for theU.S. Treasury Departmentwhich coincidentally sent him to Hollywood to function astechnical advisorfor the filmTo the Ends of the Earth(1948). Because of his appearance and very tall frame (6 feet, 6 inches), Dierkes enjoyed a long career as a character actor, often portraying villains or soldiers. In the 1953 filmShane, Dierkes portrays villain Morgan Ryker, who is the last man shot by the title character, Shane, in the final bar room shootout. One of his more memorable scenes is in the 1960 film,The Alamo. Dierkes portrays a Tennessean named Jocko, who is torn between leaving before the attack to care for his blind wife, or staying to support the Texans' cause. Understanding that if Jocko stays to fight she will likely be widowed, Jocko's wife coaxes him to stay and defend the fort, despite her disability. Dierkes died in 1975 ofemphesymaand was survived by his wife Cynthia, two sons, and two daughters.