Principal photography began in 1998. The sequences on both Artemus Gordon's and Dr. Loveless' trains interiors were shot on sets at Warner Bros. The train exteriors were shot in Idaho on the Camas Prairie Railroad.
The Wanderer is portrayed by the Baltimore & Ohio 4-4-0 No. 25, one of the oldest operating steam locomotives in the U.S. Built in 1856 at the Mason Machine Works in Taunton, Massachusetts, it was later renamed The "William Mason" in honor of its manufacturer.
During pre-production the engine was sent to the steam shops at the Strasburg Railroad for restoration and repainting. The locomotive is brought out for the B&O Train Museum in Baltimore's "Steam Days".
The "William Mason" and the "Inyo", which was the locomotive used in the original television series, both appeared in the Disney film The Great Locomotive Chase (1956). Much of the 'Wild West' footage was shot around Santa Fe, New Mexico, particularly at the western town set at the Cooke Movie Ranch.
During the shooting of a sequence involving stunts and pyrotechnics, a planned building fire grew out of control and quickly overwhelmed the local fire crews that were standing by. Much of the town was destroyed before the fire was contained.
The theatrical film was released for summer 1999. Directed by Barry Sonnenfeld, the film (without the definite article used in the series title) made substantial changes to the characters of the series, re-imagining James West as an African-American (played by Will Smith), which included, to a small degree, some of the racial issues that certainly would have made it difficult for a black man to be a United States secret service agent in the late 19th century.
However, at the end of "The Night of the Returning Dead", West and Gordon did invite an African-American character played by guest star Sammy Davis, Jr. to join the department. The film bears significant resemblance to the Batman: The Animated Series 1995 episode "Showdown" featuring Jonah Hex.
In 1997, writer Gilbert Ralston sued Warner Bros. over the upcoming motion picture based on the series. Ralston helped create the original The Wild Wild West television series, and scripted the pilot episode, "The Night of the Inferno".
In a deposition, Ralston explained that in 1964 he was approached by producer Michael Garrison who '"said he had an idea for a series, good commercial idea, and wanted to know if I could glue the idea of a western hero and a James Bond type together in the same show."
Ralston said he then created the Civil War characters, the format, the story outline and nine drafts of the script that was the basis for the television series. It was his idea, for example, to have a secret agent named Jim West who would perform secret missions for a bumbling Ulysses S. Grant.
Ralston's experience brought to light a common Hollywood practice of the 1950s and 1960s when television writers who helped create popular series allowed producers or studios to take credit for a show, thus cheating the writers out of millions of dollars in royalties.
Ralston died in 1999, before his suit was settled. Warner Brothers ended up paying his family between $600,000 and $1.5 million.