56321 is a postalcode and its consensus geometry is derived from uszcta.
{"mz:is_ceased":0,"geom:latitude":45.58047,"wof:name":"56321","counts:names_total":0,"wof:placetype":"postalcode","wof:hierarchy":[{"continent_id":102191575,"country_id":85633793,"county_id":102087719,"localadmin_id":404514223,"postalcode_id":554774011,"region_id":85688727}],"mz:is_deprecated":0,"lbl:latitude":45.581117,"geom:area":2.74E-4,"geom:longitude":-94.393149,"wof:id":554774011,"counts:concordances_total":1,"geom:type":"Polygon","wof:lastmodified":1480788127,"wof:belongsto":[85688727,102191575,404514223,85633793,102087719],"wof:concordances":{"gp:id":"12782411"},"wof:repo":"whosonfirst-data-postalcode-us","src:geom":"uszcta","wof:country":"US","counts:names_preferred":0,"gp:parent_id":"12588869","geom:area_square_m":2370998.92379,"wof:tags":[],"counts:names_variant":0,"wof:breaches":[],"edtf:inception":"uuuu","iso:country":"US","counts:names_languages":0,"geom:bbox":"-94.403926,45.573455,-94.383034,45.591404","wof:superseded_by":[],"wof:supersedes":[],"lbl:longitude":-94.391288,"wof:geomhash":"5a948669cc39b990a83dac9cfa7687ed","wof:parent_id":404514223,"wof:placetype_names":["postalcode"],"mz:hierarchy_label":1,"wof:placetype_id":470996387,"edtf:cessation":"uuuu"}