In the late 1970s and early 1980s, Stout and fellow illustrator Richard Hescox ran a Los Angeles art studio, working on such projects as the storyboards for Raiders of the Lost Ark and pop singer Michael Jackson's video Thriller.

Stout illustrated the poster art and wrote the story (and the first draft of the script) of the film The Warrior and the Sorceress for Roger Corman, as well as writing a never-produced dinosaur feature for Jim Henson.

In 1984 he illustrated The Little Blue Brontosaurus, which was a 1984 Children's Choice Award recipient and the basis for the 1988 animated feature The Land Before Time.

In 1986, as a result of his paleontological reconstruction work, eleven Stout paintings were selected for inclusion in the traveling exhibition "Dinosaurs Past and Present," an important group show depicting the history of paleoart.

In 1993, Universal Cartoon Studios chose Stout to design a prime-time animated series of Jurassic Park, which was ultimately shelved.

He made several dives beneath the ice, climbed the active volcano Mount Erebus, camped in the dry valleys, and produced over one hundred painted studies as he carefully observed Antarctica's wildlife.

Shortly thereafter, Stout drove over one thousand miles through central southern Chile, documenting the rare prehistoric forests there for inclusion in his Lost Worlds book.

In early 1998 Stout completed three Cretaceous murals and supervised two full-sized dinosaur sculptures for Disney's Animal Kingdom.

In late 1995, Steven Spielberg chose Stout as his senior concept designer for GameWorks, a Sega/Universal/DreamWorks SKG joint project.

For two years Stout and his team oversaw the concepts, design, and execution of the first three GameWorks facilities in Seattle, Washington; Tempe, Arizona; and Ontario, California).

Stout worked in 1998-1999 as the lead designer for Kansas City's Wonderful World of Oz theme park (which never opened).