(written from a Production point of view)
In an interview with John Ellis for the DVD commentary of the Steve Canyon episode "The Search" for the DVD collection Hoy revealed to Ellis that he actually was in the Horta costume in the same episode (in certain shots as a "stunt performer") and that Janos Prohaska, who created and also wore the costume, was a long time friend and coworker. 
Hoy is probably best remembered for his portrayal of Joe Butler on the Emmy Award winning western series The High Chaparral on which he worked between 1967 and 1971. TNG guest star Henry Darrow and TOS stuntman Jerry Summers were also a regulars on this show. 
Early life and career
Hoy was born in New York City, New York and worked part-time on a ranch in the Catskill Mountains between 1934 and 1944. In 1944 he enlisted as marine and was assigned to Camp Pendelton, California. He later served in World War II and was discharged in 1946 followed by a job as a cowboy on a Nevada ranch. In 1950 Hoy found himself performing horse stunts in the western Ambush and thought about a career in the stunt business. He met David Sharpe who served as his teacher and instructor and taught him the right way performing horse stunts. Also in 1950 a leg injury prohibited Hoy, as a member of the Marine Corpse Reserve, in further active duty.
The following years he performed stunts and played guards and troopers in the western series Death Valley Days, the western Wings of the Hawk (1953, along stuntmen Fred Carson and Bob Herron), the western The Lawless Breed (1953), the western The Man from the Alamo (1953), the romance The Black Shield of Falworth (1954), the drama A Star Is Born (1954, with stuntman Carey Loftin), the science fiction film Revenge of the Creature (1955), the western Raw Edge (1956), the fantasy film The Mole People (1956), and Joseph Pevney's drama Man of a Thousand Faces (1957, with Celia Lovsky).
Into the stunts
Beside doubling for actor Audie Murphy in the western Destry in 1954, Hoy was known to serve as stunt double for Tony Curtis in the Academy Award winning film The Defiant Ones. Together with Ivan Dixon, who doubled Sidney Poitier, he performed all major action scenes. The film also featured Trek performers Theodore Bikel, Lawrence Dobkin, and Whit Bissell and received Oscars for Best Cinematography and Best Writing, Story and Screenplay beside seven more nominations.
Further stunt parts include Joseph Pevney's drama Twilight for the Gods (1958), Alfred Hitchcock's thriller North by Northwest (1959, under stunt coordination of Paul Stader), Blake Edwards' comedy Operation Petticoat (1959), the western series Laramie and Johnny Ringo, the adventure series Sea Hunt (1958, starring Lloyd Bridges), the western series Have Gun - Will Travel (1958), and a recurring part as Sgt. Pete Berger in the series Steve Canyon (1959). He also portrayed a soldier in Stanley Kubrick's historical Spartacus (1960) along fellow later Trek stunt performers Paul Baxley, Bill Catching, Chuck Courtney, Dick Crockett, Louie Elias, Robert Herron, Carey Loftin, Gil Perkins, Tom Steele, and Jerry Summers and under stunt coordination of stunt icon Yakima Canutt.
In 1961 Hoy and fellow stuntmen founded the Stuntmen's Association of Motion Pictures, an organization of top stuntmen in the Motion Picture and Television industry. The SAMP later recognized him by giving him the title of a Lifetime Member, a recognition fellow Trek stuntmen Ron Burke, Hal Burton, Dick Durock, Roy Jenson, Bob Miles, and Jesse Wayne also received. The current board of SAMP features stuntmen from all incarnations of Star Trek: Shawn Crowder, Chris Doyle, Robert Herron, Loren Janes, Alex Daniels, Monte Rex Perlin, J. Mark Donaldson, Hugh Aodh O'Brien, Ben Scott, and David LeBell.
In the '60s Hoy continued to perform stunts and portray characters in film and television. Beside his work on Star Trek in 1967 and The High Chaparral (1967-1971) he worked on the television series Bonanza (1961-1965), Bat Masterson (1960-1961), Peter Gunn (1961), The Untouchables (1962, with Frank Gorshin), The Rifleman (1960-1963, with Paul Fix), Combat! (1965), The Virginian (1966), The Man from U.N.C.L.E. (1965-1966), The Green Hornet (1966), The Iron Horse (1966), and The Mod Squad (1969, starring Clarence Williams III and Tige Andrews).
Film work during this time includes the comedy It's a Mad Mad Mad Mad World (1963), the western Shenandoah (1965, with Glenn Corbett and Rosemary Forsyth), Blake Edwards' comedy The Great Race (1965), the drama Harlow (1965), the Elvis Presley comedy Tickle Me (1965), the action drama Aussault on a Queen (1966), the war drama Tobruk (1967), and the Walt Disney comedy The Love Bug (1968). In the 1966 war drama Beau Geste, Hoy served as stunt double for actor Telly Savalas under stunt coordination of Hal Needham.
The '70s and '80s
Following his long association with Bonanza and The High Chaparrel, Hoy had roles in television series such as Night Gallery (1971), Mission: Impossible (1973), Kung Fu (1972-1973), Barnaby Jones (1973, with Lee Meriwether and directed by Larry Dobkin), The Magician (1974), The Cowboys (1974, alongside DeForest Kelley), Mannix (1974), The Rockford Files (1975), The Streets of San Francisco (1973 and 1975), The Six-Million-Dollar Man (1974 and 1978), Fantasy Island (1978, starring Ricardo Montalban and directed by Cliff Bole), Wonder Woman (1978-1979), B.J. and the Bear (1979), and The Dukes of Hazzard (1979).
In the '80s he focused more on acting and appeared in Hawaii Five-O (1980, with Jack Lord), Vega$ (1981), Quincy M.E. (1981), Little House on the Prairie (1975-1982), Father Murphy (1982), The Master (1984), The Fall Guy (1982 and 1985), Airwolf (1985), North and South (1985, with Kirstie Alley, James Read, and Jim Metzler), Magnum, P.I. (1981-1986), and Beauty and the Beast (1988, starring Ron Perlman). He had recurring roles as Detective Howard in the drama series Dallas (1978-1982, starring Susan Howard) and as Cliff in the drama series Our House (1986-1988, starring Chad Allen).
His film credits throughout these two centuries include the science fiction film Earth II (1971, starring Gary Lockwood and Mariette Hartley), the television thriller A Cry in the Wilderness (1974), the television movie Barbary Coast (1975, starring William Shatner), the television drama Helter Skelter (1976), the action thriller The Enforcer (1976), the drama Steel Cowboy (1978), Clint Eastwood's drama Bronco Billy (1980), the adventure The Legend of the Lone Ranger (1981, with Christopher Lloyd), the science fiction film Choke Canyon (1986, with Stephen Collins), the comedy Legal Eagles (1986), and the television special Bonanza: The Next Generation (1988, with Peter Mark Richman).
After he worked on a number of films and television series as second unit director/ stunt coordinator, Hoy joined the Director's Guild of America in 1990 and worked as director and assistant director on several episodes of the television series Zorro in Spain. Zorro, which was mostly filmed in Spain, was filmed between 1990 and 1993 and starred Duncan Regehr in the title role and Hoy's fellow The High Chaparrel co-star Henry Darrow as Zorro's father Don Alejandro de la Vega. The series also featured Trek actor J.G. Hertzler in a recurring role.
Beside his work on Zorro, Hoy appeared as Flynt in two episodes of the western series The Young Riders (1989 and 1991) along Trek performers Brett Cullen, Yvonne Suhor, and Anthony Zerbe and as Judge Radford in the Walker, Texas Ranger episode "Blue Movies" (1995, with Noble Willingham and Sherman Howard). In 1994 he worked as stunt double for actor Wilford Brimley on the fantasy drama Heaven Sent followed by roles in the military series JAG and Pensacola: Wings of Gold.
His last known film work are supporting roles as himself in the comedy Big Chuck, Little Chuck in 2004 along Tony Brubaker and as "Man in Next Bed" in the television crime drama Detective in 2005. The latter film also featured Trek performers Jimmy Bennett, Christopher Lloyd, Eliza Coleman, Clint Lilley, and Richard Riehle. He also had a part in the 2007 Navy NCIS: Naval Criminal Investigative Service episode "Lost and Found" under the stunt coordination of Diamond Farnsworth.
As stuntman who doubled for actors Charles Bronson, Audie Murphy, Tony Curtis, Telly Savalas, Robert Vaughn, and Tyrone Power he was included into the Stuntmen Hall of Fame and for his contribution to the western genre he received the Golden Boot Award from the Motion Picture and Television Fund on 28 January 2010. Hoy was a member of the Academy of Motion Pictures, Arts and Sciences, the Director's Guild of America, the Screen Actor's Guild, the American Federation of Television and Radio Artists, and the Stuntmen's Association of Motion Pictures.