She has also appeared in Regional theatre productions at such theatres as the Kennedy Center, the Walnut Street Theatre, the Alley Theatre, the Goodspeed Opera House, and Syracuse Stage to name just a few.
Syracuse | Syracuse, New York | Syracuse University | stage name | Syracuse, Sicily | stage | Syracuse Orange | Syracuse Chiefs | The Stage | Portland Center Stage | Dionysius of Syracuse | Center Stage | 2013–14 UEFA Europa League group stage | Taking the Stage | Stage (theatre) | Stage Door Canteen | Single-stage-to-orbit | MCA Stage | Key Stage 3 | International Alliance of Theatrical Stage Employees | Syracuse Stage | Syracuse Orange men's basketball | Syracuse China | Northern Stage | Key Stage 2 | End stage renal disease | Downtown Syracuse | Dionysius I of Syracuse | Carry On series on screen and stage | Canadian Stage Company |
Theatres in which Appel worked include Intiman Theatre, the Guthrie Theater, Indiana Repertory Theatre, Seattle Repertory Theatre, South Coast Repertory, PlayMakers Repertory Company, Arizona Theatre Company, Alliance Theatre Company, Milwaukee Repertory Theater, New Mexico Repertory, The Goodman Theatre, Court Theatre, Syracuse Stage, Repertory Theatre of St. Louis, San Jose Repertory Theatre, Utah Shakespearean Festival, and the Alabama, Colorado and Kern Shakespeare Festivals.