I admit I have ulterior motives for asking, as I’m currently looking for a playwright/bookwriter to work on a new musical with me, but I’m also just generally curious. I know we have lots of novelists and short story writers, and some screenwriters, but do we have any good old-fashioned playwrights around these parts?
I wrote a Christmas play in 5th grade that was performed in all 4 classrooms, but I’m pretty sure that’s not what you’re looking for. 
I’ve had several children’s plays published in Plays: The Drama Magazine for Young People, and I know at least one of them was staged.
I’ve written plays for local groups, a whole lotta unproduced plays, and a science fiction mystery radio drama that I also produced, directed, and ran on the radio in Salt Lake City more years ago than I care to think about.