To most Americans, a windmill refers to a metal windpump. There are
however a scattering of more traditional "grist" mills to be found in
various states, as well as some modern constructions built to celebrate the
heritage of individual communities.
This page includes a selection of the windmills of the USA.
There's not much demand for grist mills in the desert, so it probably comes as
no surprise that the most windmill like structure to be found in the state of
Nevada was a windpump associated with a casino - the El Rancho casino which
was the first themed resort to open in Las Vegas.