Cactus Mack was a talented musician. He played violin with Ray Whitley's Six Bar Cowboys and guitar with Fred Scott's The Cimarron Cowboys. He later played villain roles in many westerns, along with other character parts.
Cactus appeared in 21 Gene Autry films and 14 Roy Rogers films, along with well over one hundred Western Movies. He appeared in several TV Series including the The Roy Rogers Show (1956) ― Lawman (1959-1962) ― Bonanza (1960-1961) ― Cisco Kid (1951-1952) ― Maverick (1957-1960)― Stagecoach West (1960-1961) ― Have Gun - Will Travel (1958-1960) ―  Cheyenne (1957-1961) ― The Rifleman (1960-1961) ― Bat Masterson (1960) ― Law of the Plainsman (1959) ― Sugarfoot (1957 -1959) ― Texas John Slaughter: The Slaughter Trail (1958-1959) ― Frontier Doctor (19597) ― Tales of Wells Fargo (1957) ― Zorro (1957) ― Sergeant Preston of the Yukon (1955) ― Frontier (1955) ― Soldiers of Fortune (1955) ― Stories of the Century (1954) ― The Adventures of Kit Carson (1950-1951) ― The Gene Autry Show (1950) ― he also appeared in forty-eight episodes of Gunsmoke (1957-1961).

He taught Roy Rogers to play the guitar when he was 16-year-old Leonard Slye.

He was known as a Cowboy Singer, Guitar Player, and Bullwhip Master.

He was a cousin of cowboy actors Rex Allen Sr. and Glenn Strange.