[10] He achieved fame in the regional and independent circuits, as well as World Championship Wrestling (WCW), as "Dirty" Dutch Mantell.

Mantel was instrumental in the careers of several huge wrestling stars of the nineties, including the Blade Runners, who later went on to achieve fame as Sting and The Ultimate Warrior.

Mantell originally considered giving Austin the stage names of either "Stevie Rage" or "William Stevenson III".

[12] Mantel formed several tag teams throughout his career, including The Kansas Jayhawks (with Bobby Jaggers), and The Desperados, which lasted only two months.

Mantel achieved his greatest notoriety in 1979 when he and then-partner, Cowboy Frankie Laine, as Los Vaqueros Locos, sold out the 16,000-seat Hiram Bithorn Stadium in San Juan, Puerto Rico for an unprecedented nine weeks in a row, a record that still stands.

In 1986, after Lawler lost a "Loser Leaves Town" gimmick match against Bill Dundee, Lawler and Mantell finally mended their ways long enough to face Dundee and Buddy Landel in a Texas Tornado Death Match in Memphis' Mid South Coliseum in front of a sold out red hot Memphis crowd.

He was the last USWA Unified World Heavyweight Champion defeating Jerry Lawler on August 8, 1997, in a Title vs All Body Hair match.

Then he went to WWC rival promotion International Wrestling Association as a creative consultant, which included writing/producing and booking four hours of original TV programming per week.

In 2003, Mantel began work behind the scenes as a writer/producer/agent for TNA Total Nonstop Action Wrestling and as a full-time member of the booking/creative team.

Mantel was instrumental in several successful creations for the company, most notably the TNA Knockouts division that helped to reinvigorate interest in women's wrestling in the United States.

[13] In November 2009, Reno Riggins, announced that Dutch would be joining Showtime All-Star Wrestling promotion out of Nashville as a writer and on air talent.

Mantel wrote the book in around 5 weeks, while sitting on a beach on Isla Verde, Puerto Rico, with assistance from editors Ric Gross and Mark James.

The event honored Bruno Sammartino with several modern and legendary wrestlers including Carlito, Kamala, Scott Steiner, Tommy Dreamer, Christy Hemme, Bob Orton, Nikolai Volkoff and The Iron Sheik.

The Real Americans experienced little success, losing to Los Matadores at Hell in a Cell PPV and a Fatal 4-Way tag team match at TLC.

In a storyline described by Rolling Stone as "the wildly unpopular MexAmerica storyline",[20] Colter returned at Hell in a Cell 2015, utilizing a mobility scooter, where he announced that the returning Alberto Del Rio would answer John Cena's Open Challenge for Cena's United States Championship, where Del Rio was victorious.

[27] Following his release from WWE, it was confirmed that Mantel signed to appear at a show co-promoted by Global Force Wrestling and WrestlePro on June 11, 2016.

Mantel left Impact Wrestling in December 2017 after Don Callis and Scott D'Amore took over as Executive Vice Presidents.

[7][8] Keown regularly appeared as Zeb Colter in the WWE web series The JBL and Cole Show, until its cancellation in June 2015.

In November 2024, a GoFundMe appeal was launched to help Mantel and his family pay for medical bills after he and his wife had a series of stays in hospital due to serious health issues including sepsis.