Sanctuaries in the Snow

The Walter's Home Run Sign (Buttermilk)

The Walter's Home Run sign is on Buttermilk.  Does anyone know who Walter is or was, or know anything about the meaning of this sign that would be appropriate to add to this page?  If so, please e-mail the author at [email protected].  Photos of the sign, taken in April 2017, are below (click on images to enlarge).