• in 1926, high schooler Tris was in the play "Boomerang" which was presented by the East High School drama club in Salt Lake City.
• was in the cast of "The Spring Maid" during Salt Lake City's Summer, 1927 Civic Opera season.
• he was in the cast of "Within the Law" and "The Woman of Bronze" at Salt Lake City's Playhouse Theater in 1930.
• in 1931, he was in the Sigmund Romberg opera "New Moon" with the Civic Opera in Salt Lake City.
• In Murray City, Utah in 1931, he was with the Stewart-Reid Players in "The Bad Man" and "Hell Bent Fer Leather" and with the Little Theater group in "Tommy". (Murray City is about 8 miles south of Salt Lake City).

Ancestry.com has the 1926 yearbook for Salt Lake City's East High School and there's photos of Tristam [sic] Coffin in R. O. T. C. and acting in the play "Boomerang".

Some bios have him attending college at the University of Utah, and later, graduating from the University of Washington. I contacted the Registrar at both universities:

University of Utah Registrar: " I did not find any record of Tris Coffin having attended the University of Utah."

University of Washington Registrar: "... we were unable to locate anyone with that name having attended the University of Washington."

His college attendance appears to be resolved in a 1958 newspaper article and interview - excerpt: "Coffin ... came east, studied at the Leland Powers School of acting in Boston, later taught there, then went into radio, movies and television." (Financial issues caused Boston's Leland Powers School of Radio and Theater to close in April, 1979.)

In the 1930s, Tris was an announcer and newscaster on Boston radio stations WNAC and WAAB. Unsure when he moved to Boston, but there are trade publication mentions of him during June, 1934 - March, 1938. And October, 1934 issues of Microphone and Radio Guide magazines noted that WNAC announcer Tristram Coffin married Dorothy Whitcomb in Boston.

RKO persuaded him to give Hollywood a try, and among his initial batch of films was an uncredited role as a newscaster in THE SAINT STRIKES BACK (RKO, 1939). Other early film employment were 1939 releases in Monogram's Jack Randall oaters and cliffhanger DICK TRACY'S G-MEN (Republic, 1939).

Coffin became a busy freelancer. Good looking and with a great voice, he often portrayed smart, slick and slippery villain and authority figures. His movie and TV career spanned about thirty years and amounted to approximately 175 films, and about a third were westerns and serials.

In 1939 - 1957, he appeared in about 35 films at Republic Pictures, and those were a mix of oaters, serials, and other features. At Monogram, he did about three dozen scattered over the years 1939 - 1951 and most were B westerns. He often played a gangster, gambler, or spy, and you can spot him in Republic and Columbia cliffhangers such as HOLT OF THE SECRET SERVICE, SPY SMASHER, THE PERILS OF NYOKA, and FEDERAL AGENTS VS. UNDERWORLD, INC.

As the B western and serial faded in the post World War II years, Coffin migrated to TV and appeared in I LOVE LUCY, SUPERMAN, WILD BILL HICKOK, FATHER KNOWS BEST, CISCO KID, lots more.

He occasionally played a hero - highlights:

• In THE CORPSE VANISHES (Monogram, 1942), it was Coffin and pretty Luana Walters vs. Bela Lugosi.
• He starred as "Jeff King" in Republic's 1949 cliffhanger KING OF THE ROCKETMEN.
• Coffin was "Captain Tom Rynning" in the syndicated 26 MEN TV series. 78 half-hour episodes were filmed and broadcast 1957 - 1959 on ABC.
• Among his many television jobs was portraying "Captain Reid", the Texas Ranger brother of the Lone Ranger, who gets gunned down by Butch Cavendish (Glenn Strange) and gang in the TV series opener titled "Enter the Lone Ranger" (which was originally broadcast September 15, 1949).
• He had a featured role as "Police Lieutenant Doyle" on the syndicated TV mystery THE FILES OF JEFFREY JONES (1952) on CBS which starred Don Haggerty and Gloria Henry.

Coffin served in the Navy during World War II. And he was married twice. As noted earlier, he and Dorothy Whitcomb married October, 1934 in Boston. And on December 30, 1947, he tied the knot with Vera Duke Herman, and they were together through his passing in 1990. No children from either marriage.

Coffin was well liked and respected by his peers, and one of his closest friends was Clayton Moore. In Moore's bio I Was That Masked Man (Taylor Publishing, 1998) by Moore and Frank Thompson, the Coffin / Moore friendship is highlighted on page 66:

"I met Tristram Coffin on the set of The Perils of Nyoka, too. He was a wonderful character actor who often played in Republic, Monogram, and other low-budget studios' films and serials. He told me that he had been one of the radio reporters covering the kidnapping of the Lindbergh baby a few years earlier. Tris and I worked together often over the course of our careers; we became close friends. A few years later, he would be cast as my older brother, Dan Reid, in the opening episode of The Lone Ranger." (The Lindbergh baby kidnapping was 1932.)

According to original and amended death certificates, Tristram Chalkley Coffin was born August 13, 1909 in Utah to Edwin Coffin and Elizabeth Christie Coffin. He passed away on March 26, 1990 at St. John's Medical Center, Santa Monica, California, and cause of death was cardiopulmonary arrest due to respiratory failure, COPD, and lung cancer. He and wife Vera Duke Coffin lived in Santa Monica; occupation was "Actor"; Pierce Bros. was the funeral director; and his cremains were to be scattered in the Pacific Ocean off Long Beach, California.

I have a lot of respect for Tris Coffin because of his versatility in playing big and small roles in films and TV. Whether portraying the brains heavy, henchman, or authority figure, he was smart, stylish, debonair ... smooth. Definitely more brains than muscle and bulk. In his few times as a hero, he was solid, believable. And when the serial and B western faded away, he did a career adjustment and became a busy television performer.

Ancestry.com had the 1926 yearbook for East High School in Salt Lake City. There's a full page of photos of the high schoolers that performed in the play "Boomerang", and above is a crop of Tris and an unidentified actress in that play. He was about 16 1/2 years old, and in the cast listing, his name is misspelled as Tristam. (Courtesy of Minard Coons) Max 'Alibi' Terhune and his pal Elmer versus cardsharp Tris Coffin in the Range Busters adventure WEST OF PINTO BASIN (Monogram, 1940). In this, Alibi loses the Busters horses in a poker game and Ray 'Crash' Corrigan wins them back by busting up Tris Coffin's card game trickery. PINTO BASIN was released in late 1940, and Coffin was 31 years old when he did this oater.

Left is a screen capture of Luana Walters and Tris Coffin from the colorized version of THE CORPSE VANISHES (Monogram, 1942). Their adversary was Bela Lugosi.

(From Old Corral collection) L-to-R are Christine Larsen/Larson, Tris Coffin, Andy Clyde, Whip Wilson, Steve Darrell, and unidentified player on the right in CRASHING THRU (Monogram, 1949), Wilson's first starring film. (From Old Corral collection) Lobby card with Coffin starring in the serial KING OF THE ROCKETMEN (Republic, 1949). Is the security guard Harry Strang? Tris Coffin on the right, and partial face of Kelo Henderson on the left. Ad for their syndicated 26 MEN TV series from a 1958 Broadcasting Telecasting magazine available at the Internet Archive. 26 MEN was churned out by Russell Hayden's production company. 78 half-hour episodes were filmed and broadcast on ABC in 1957 - 1959. (Courtesy of Minard Coons) Above and below, Tris Coffin at one of the 1970s film conventions. Photo below shows some good natured hijinks between three cowboy and serial bad guys - Tris Coffin is about to pummel Terry Frost, while a smilin' George J. Lewis looks on. (Courtesy of Minard Coons)

  Although some of the data is incomplete or inaccurate, the Internet Movie Database (IMDb) has information on Tris Coffin: https://www.imdb.com/name/nm0168939/

Daniel Neyer's "The Files of Jerry Blake" website has a webpage on Tris Coffin in serials: https://filesofjerryblake.com/serial-character-actors-2/tristram-coffin/

February 12, 1926 Salt Lake Tribune has a photo and article on the East High School Dramatic Club in the play "The Boomerang" at the school auditorium. Photos are labeled and photo numbers 1 and 4 are 16 1/2 year old Tristram Coffin: https://www.newspapers.com/article/the-salt-lake-tribune-future-movie-and-t/136235798/

Internet Archive has the February, 1959 issue of TV Radio Mirror magazine with a large article and many photos of Tris Coffin (and wife Vera) during the filming of the 26 MEN TV series in Scottsdale, Arizona: http://archive.org/details/radiotv00mac/page/n101/mode/2up?view=theater

January 25, 1958 Hartford, Connecticut Courant newspaper has a full page article on Coffin, Kelo Henderson, and the 26 MEN TV show. Mentions him attending and working at the Leland Powers School of acting in Boston: https://www.newspapers.com/article/hartford-courant/22507634/

On the trail of Tris Coffin:

• Birth certificate for Tristram Chalkley Coffin. He was born August 13, 1909 in Mammoth, Juab County, Utah to Edwin Coffin (born Iowa; occupation "Miner)" and Elizabeth Christrie (born Utah; "Housewife"): https://www.familysearch.org/ark:/61903/1:1:QL37-52D7
• 1910 census - living in Mammoth, Juab County, Utah were 54 year old Edwin C. Coffin (born Iowa; occupation "Superintendent - Silver Mine"), his 28 year old wife Elizabeth (born Utah; no occupation listed), and children Macy, Ethel, Jackson, Edwin, and 8 month old son Tristram: https://www.familysearch.org/ark:/61903/1:1:M5XC-62Q
• 1920 census - living in Salt Lake City, Salt Lake County, Utah were 63 year old E. C. Coffin (born Illinois; occupation "Secretary Treasurer - Coal Company"), his 38 year old wife Elizabeth (birth location not listed), 7 year old son Boyd and 10 year old son Tristram: https://www.familysearch.org/ark:/61903/1:1:M8PV-16Z
• 1930 census - owning their home in Salt Lake City, Utah were 75 year old Edwin C. Coffin (born Iowa; occupation "Manufacturers Representative - Hardware Trades"), his 48 year old wife Elizabeth (born Utah; occupation "Cashier - Grocery"), and sons Tristram C., Boyd S., and Edwin C. III. Son Tristram C. Coffin was 20 years old, born in Utah and occupation was "Actor - Stock Company": https://www.familysearch.org/ark:/61903/1:1:XH6J-SQ7
• Internet Archive had the October 26, 1934 The Microphone and October 27, 1934 Radio Guide magazines with an announcement that Dorothy Whitcomb and Tristram Coffin had married. He was an announcer on Boston radio stations WNAC and WAAB.
• Ancestry.com had the 1936 Boston City Directory - living in Boston were Tristram Coffin (occupation "Announcer") and wife Dorothy.
• January 10, 1938 Salt Lake Tribune had a death notice for Tris' father, Edwin C. Coffin, who passed away on January 9, 1938. Survivors included his wife Elizabeth Christie Coffin of Salt Lake City and son Tristram C. Coffin of Boston: https://www.newspapers.com/article/the-salt-lake-tribune-death-notice-for-e/136787664/
• ProQuest had the World War II draft registration dated October 16, 1940 for Tristram Chalkley Coffin - has an incorrect birth location. He was born August 13, 1909 in Charlottesville, Virginia; he and wife Dorothy lived at 151 North Swall Drive, Beverly Hills, California; and his occupation was "Free Lance Actor". He was 6 feet, 1 inch in height and weighed 180 pounds.
• Ancestry.com had the U.S., Department of Veterans Affairs BIRLS Death File - Tristram C. Coffin was born August 13, 1911 and served in the Navy from January 13, 1943 to October 18, 1945.
• February 16, 1943 Deseret News had a death notice for Tris' mother, Elizabeth C. Coffin, who passed away on February 15, 1943 in Santa Monica, California. Survivors included son Tristram C. Coffin who was a Seaman First Class stationed at Norfolk, Virginia: https://www.newspapers.com/article/deseret-news-death-notice-for-elizabeth/136842627/
• California Marriage License - Tristram Coffin and Vera Herman married on December 30, 1947 in Los Angeles. Was his second marriage and her third. (Marriage license and Family trees indicate her birth name was Vera Duke.): https://www.familysearch.org/ark:/61903/1:1:K8K2-7CJ
• 1950 census - living at 332B Oakhurst Drive, Beverly Hills, California were 38 year old Tristram C. Coffin (born Utah; occupation "Screen actor - Movie Industry") and his 28 year old wife Vera D. (born Oklahoma; occupation "Waitress - Cocktail Lounge"): https://www.familysearch.org/ark:/61903/1:1:6XG7-PL3K
• The California Death Index as well as the Social Security Death Index (SSDI) have records on Tristram Chalkley Coffin - he was born 8/13/1909 and passed away on 3/26/1990. SSDI has him born in Massachusetts while the California Death Index has Utah:
  https://www.familysearch.org/ark:/61903/1:1:VP2T-RBX
  https://www.familysearch.org/ark:/61903/1:1:JB27-XJQ
• According to original and amended death certificates, Tristram Chalkley Coffin was born August 13, 1909 in Utah to Edwin Coffin and Elizabeth Christie Coffin. He passed away on March 26, 1990 at St. John's Med Center, Santa Monica, California, and cause of death was cardiopulmonary arrest due to respiratory failure, COPD, and lung cancer. He and wife Vera Duke Coffin lived at 2314 Pier Avenue, Santa Monica, and Vera was the death certificate informant; his occupation was "Actor"; Pierce Bros. was the funeral director; and his cremains were to be scattered in the Pacific Ocean off Long Beach, California.
• Death announcement for Tris Coffin in the April 1, 1990 Los Angeles Times newspaper: https://www.newspapers.com/article/the-los-angeles-times-death-announcement/136196319/
• Find A Grave website notes that Coffin was cremated and ashes scattered: https://www.findagrave.com/memorial/11692630