While still living in New York in the 1970s, Mario received several commissions to paint murals in Denver, and these trips eventually led to his relocation there.
Despite his skill as a painter and draftsman, Mario's favored medium was assemblage. He collected buttons, game pieces, and every other kind of small object and liberally worked them into the lavish decoration of anything - from furniture to clothing to jewelry.
He showed his elaborate pieces in galleries across the country, including Julie's Artisan's Gallery in New York City, Pismo Gallery in Denver, as well as Lewis Bobrick Antiques in Denver. For years Mario participated in the World Wide Antique Show in Denver as well as other national antique shows. He also operated his own antique shop, Finders Keepers, in Denver, where he would sell his artwork along with antiques.
Mario also revived the home-craft of beaded flower making, and took the art form to a new level of creativity and excellence in the past twenty years.
Mario's work is in many public and private collections. Most recently (2019-2020) some of his clothing pieces were featured in "Off the Wall: American Art to Wear" at the Philadelphia Museum of Art.