Rockford is a marketarea and its consensus geometry is derived from whosonfirst.
{"name:epo_x_preferred":["Rockford"],"name:jpn_x_preferred":["ロックフォード"],"geom:latitude":42.110093,"name:nds_x_preferred":["Rockford"],"name:vol_x_preferred":["Rockford"],"wof:controlled":["wof:parent_id","wof:hierarchy"],"wof:name":"Rockford","counts:names_total":22,"name:ceb_x_preferred":["Rockford"],"mz:is_current":1,"wof:hierarchy":[{"continent_id":102191575,"country_id":85633793,"empire_id":136253057,"marketarea_id":1360665431}],"name:ara_x_preferred":["روكفورد"],"name:srp_x_preferred":["Рокфорд"],"lbl:latitude":42.111856,"name:por_x_preferred":["Rockford"],"geom:area":0.805826,"name:bre_x_preferred":["Rockford"],"name:kor_x_preferred":["록퍼드"],"counts:concordances_total":2,"geom:type":"Polygon","wof:lastmodified":1583789566,"wof:belongsto":[102191575,85633793,136253057],"name:rus_x_preferred":["Рокфорд"],"mps:latitude":42.111856,"wof:repo":"whosonfirst-data-admin-us","wof:country":"US","counts:names_preferred":21,"geom:area_square_m":7.391942312119554E9,"name:swe_x_preferred":["Rockford"],"counts:names_variant":1,"wof:breaches":[],"edtf:inception":"uuuu","iso:country":"US","geom:bbox":"-89.926641,41.584889,-88.705186,42.505818","name:spa_x_preferred":["Rockford"],"name:eng_x_preferred":["Rockford"],"wof:superseded_by":[],"name:fra_x_preferred":["Rockford"],"name:nld_x_preferred":["Rockford"],"wof:geomhash":"0329b8851f94f22a823bbedccc448330","wof:placetype_id":1360666019,"mz:is_ceased":0,"wof:placetype":"marketarea","name:ita_x_preferred":["Rockford"],"mz:is_deprecated":0,"geom:longitude":-89.304956,"wof:id":1360665431,"wof:concordances":{"digitalenvoy:metro_code":610,"nielsen:id":610},"name:eng_x_variant":["Rockford, IL"],"name:cat_x_preferred":["Rockford"],"src:geom":"whosonfirst","name:pol_x_preferred":["Rockford"],"name:fin_x_preferred":["Rockford"],"wof:tags":[],"counts:names_languages":21,"mps:longitude":-89.304895,"wof:supersedes":[],"lbl:longitude":-89.304895,"wof:parent_id":85633793,"wof:placetype_names":["marketarea"],"mz:hierarchy_label":0,"edtf:cessation":"uuuu","name:deu_x_preferred":["Rockford"]}