Born in San Francisco in 1952, Thom has had a lifelong interest in American History and the “folk hero” who is a product of that history and has long been the motivating force behind his work. His emphasis, however, is focused on the historical “folk hero” as compared to the mythical “folk hero." (An example of the historical folk hero would be Jesse James, a mythical folk hero would be Paul Bunyan; one actually existed while the other is a product of tall tales.)

Ross works in various media including painting, book illustration and life-sized recreations of historical scenes. Favorite subjects include: Cowboys, Indians and historical battles in the American Indian Wars. Ross has illustrated at least 20 books, including a history of baseball. In 2001, Ross published a book, Gunfight at the O.K. Corral in Words and Pictures. In 2002, Ross illustrated the 100th anniversary edition of Owen Wister's novel, The Virginian.

Ross' first plywood installation was a 1976 cutout of Clint Eastwood, which he and a friend placed as a prank above a railroad trestle to recreate a scene from Dirty Harry in the location where the scene had been filmed five years earlier. In 1983, Ross created "154 Nevermore" - an installation of 154 plywood ravens on a highway in Jackson, Wyoming (recreated in steel in 2000). In 1984, Ross created "The Catch"- a diorama for the Baseball Hall of Fame illustrating a legendary catch with the same nickname by Willie Mays in the 1954 World Series. He created a new version of the work in 2004, and displayed it in various locations in New York City. In 1998, Ross created "The Defining Moment" for SAFECO Field, a tableau of 11 steel cutouts of a Ken Griffey, Junior play in the 1995 baseball playoffs. Ross' 2005 work, "Custer's Last Stand", was a recreation of life-sized warriors riding life-sized horses in the Battle of Little Bighorn at the original site at Medicine Tail Coulee in Montana. That exhibit toured Cody, Wyoming, Jackson, Wyoming, and Sun Valley, Idaho. In September 2008, Ross recreated a 1902 photograph of Buffalo Bill Cody and his "Wild West Show" and his traveling troupe of Native Americans, in front of the Cliff House at Ocean Beach in San Francisco.