Where can i find elegant dresses for tall women in Scottsdale?

I'm 6'2 and about a size 12-14 dress size. I have an elegant event coming up and can't find a dress to fit my height anywhere. Does anyone know any great stores / boutiques in the Scottsdale / Phoenix area? I try to support local designers and boutiques as opposed to the brands and most of the dept stores don't have things that fit my height either. Please help me find something glamorous and tasteful a la Escada / St. Johns type of style.