Keppel is also a playwright and co-artistic Director of the Rock River Players in Williamsville, Vt. His plays have been presented at the Boston Playwrights’ Theatre and the Huntington Theatre’s Studio 210 , the Boston University School for the Arts, and the Isabella Stewart Gardner Museum. In 2011, with the support of the Jim Henson Foundation, Keppel and composer Brad Kemp ’02 created a multimedia version of his play Triangle, which was performed in March 2011 at the Center for Performance Research in Brooklyn, N.Y., during the centennial of the Triangle fire. Keppel and Kemp were subsequently awarded a Henson Project Grant, resulting in a June 2013 residency and performance of Triangle at the Sandglass Theater in Putney, Vt., and a January 2014 production at NEC as part of the Music: Truth to Power festival. Last year a version of Triangle was produced by the Rock River Players in Williamsville, Vermont, and in 2025 his play The Freeing of Mollie Steimer will have its premier there.

Keppel is also a writer of fiction. Stories from his collection of fiction, The Monologist, have appeared in The Literary Review, The Berkeley Fiction Review, Tamaqua, and the entire collection is featured on the web journal Web Del Sol. In 2004 his story “A Vectorial History of Leroy Pippin” was read by Eli Wallach at Symphony Space in New York as part of NPR’s Selected Shorts program.