Mari Lyons studied at Mills College (with Max Beckmann and Fletcher Martin), Bard College (Louis Schanker, Ludwig Sander, Stefan Hirsch), BA, Atelier 17 (Stanley William Hayter), the Grand Chaumiere, Yale-Norfolk Art School (Bernard Chaet, Gabor Peterdi), and Cranbrook Academy of Art (Zoltan Zepeshy, Madison Fred Mitchell), MFA. She exhibited widely throughout the country and one of her Montana landscapes traveled to Tunis as part of the Art in Embassies Program of the U.S. Department of State. Her work is represented in Climate Central Foundation, The Museum of the City of New York, Montana State University Library, Rider University, the DeGolyer Library (SMU), and elsewhere, and in more than 120 private collections.
She had fifteen one-person shows at First Street Gallery in New York City, along with one and two-person shows at Rider University, Fairleigh Dickinson University, Kirkland Art Center in Clinton (NY), Windham Fine Arts in Windham (NY), Polari Gallery in Woodstock (NY), the Forsythe Gallery in Ann Artbor (MI); and elsewhere.
Mari was married to the writer and book publisher Nick Lyons and their family includes four children and four grandchildren. She maintained studios in New York City and Woodstock, New York.