59803 is a postalcode and its consensus geometry is derived from uszcta.
{"mz:is_ceased":0,"geom:latitude":46.793924,"wof:name":"59803","counts:names_total":0,"wof:placetype":"postalcode","mz:is_current":1,"wof:hierarchy":[{"continent_id":102191575,"country_id":85633793,"county_id":102085103,"postalcode_id":554733001,"region_id":85688617}],"mz:is_deprecated":0,"lbl:latitude":46.795744,"geom:area":0.024438,"geom:longitude":-113.962836,"wof:id":554733001,"counts:concordances_total":1,"geom:type":"Polygon","wof:lastmodified":1611184224,"wof:belongsto":[102191575,85633793,102085103,85688617],"wof:concordances":{"gp:id":"12783849"},"wof:repo":"whosonfirst-data-postalcode-us","src:geom":"uszcta","wof:country":"US","counts:names_preferred":0,"geom:area_square_m":2.06878158963986E8,"wof:tags":[],"counts:names_variant":0,"wof:breaches":[],"edtf:inception":"uuuu","iso:country":"US","counts:names_languages":0,"geom:bbox":"-114.098796,46.708105,-113.843136,46.877219","wof:superseded_by":[],"wof:supersedes":[],"lbl:longitude":-113.938072,"wof:geomhash":"dd3668bc5f0316653ed45ff2d2867ae1","wof:parent_id":102085103,"wof:placetype_names":["postalcode"],"mz:hierarchy_label":1,"wof:placetype_id":470996387,"edtf:cessation":"uuuu","mz:postal_locality":"Missoula"}