pittsburgh mills was conceived and originally developed by the mills corporation, now simon property group. on december 30, 2006, it was announced that the mills corporation sold its stake in pittsburgh mills to its partner in the project, zamias services, inc. of johnstown. because of this, pittsburgh mills is currently the only mills-branded mall that is neither owned or managed by simon in the united states. vaughan mills near toronto and the recently opened crossiron mills outside calgary, alberta, are the only other mills-type malls that are not owned or managed by simon. to date, it is the last mills mall built in the united states.