Frost began his career in 1941 as Sam Emery in the film Law of the Range. He spent the 1940s and 1950s appearing in dozens of B-moviewesterns for the studios Monogram and PRC, including roles in The Maverick, Outlaws of Texas, The Girl from Monterey, and "Desert Legion." During the 1950s Frost was heavily involved with television. He appeared often in series TV, with feature roles on many, such as "I Lead Three Lives," "Waterfront," "Boston Blackie," "Mr. Districk Attorney," and a recurring role as Sergeant Morris in the Brodrick Crawford series, "Highway Patrol." Terry appeared in almost every Western series ever produced, from The Gene Autry Show to Gunsmoke to Rawhide and Annie Oakley, as well as a 1955 episode of The Lone Ranger. During the 1960s his acting career slowed considerably, with his last film appearance in Magnifico extranjero, El in 1967. During this period Terry taught drama in Los Angeles, authored a text on the art of acting, and worked in regional theatre throughout the USA. Wanderlust led him to travel the world, and he visited every continent, proclaiming New Zealand the most beautiful place on Earth. Once retired, Terry became a popular guest speaker at various B-Western conventions in the US and the British Isles, where he entertained the audiences with reminiscence about everyone from Johnny Mack Brown to Whip Wilson. He died of a heart attack.