Mantooth has frequently returned to his theatre roots in such productions as "Arsenic and Old Lace" at the Alhambra Dinner Theatre in 1983, and "The Man With The Dirty Mind" with Don Knotts and Rue McClanahan. In 1984, Mantooth worked with David Carradine and Will Sampson, along with other Native actors, in a production of "Black Elk Speaks" for the American Indian Theatre Company in Tulsa, Oklahoma. Mantooth continued to do theatre with roles in a variety of plays including Edith Villareal's "Crazy from the Heart" at the Yale Repertory Theatre in 1986, and Mark Kaufman's "Evil Little Thoughts" at the Denver Center Theatre in 1991, Mantooth, along with James Van Der Beek performed Lanford Wilson's "Rain Dance" off-Broadway at the Signature Theatre. Mantooth has also performed in three works written by William S. Yellow Robe, Jr.: "The Pendleton Blanket", "Wink-Dah" and "The Independence of Eddie Rose".