Well I wrote a quick script using the algorithm I outlined above and spit out a formula.
I think the general idea is true that zip codes for a county are within certain upper and lower bounds but there appear to be exceptions you would have to hunt down.
Oddly the first test in the formula for zip code 00501 is an IRS Service Center out of sequence from the other zip codes for Suffolk County:
https://www.unitedstateszipcodes.org/00501/I know there are so called "stealth" zip codes for US Marshal Servcies, Military Installations, Area 51 and apparently the IRS. I will contact Mulder & Scully and see if they have any insight.
var Number z = ToNumber([ZipCode]);
If(
501 <= $z and $z <= 11980, "Suffolk, NY",
601 <= $z and $z <= 601, "Adjuntas, PR",
602 <= $z and $z <= 602, "Aguada, PR",
603 <= $z and $z <= 690, "Aguadilla, PR",
606 <= $z and $z <= 606, "Maricao, PR",
610 <= $z and $z <= 610, "Anasco, PR",
611 <= $z and $z <= 641, "Utuado, PR",
612 <= $z and $z <= 688, "Arecibo, PR",
617 <= $z and $z <= 617, "Barceloneta, PR",
622 <= $z and $z <= 623, "Cabo Rojo, PR",
624 <= $z and $z <= 624, "Penuelas, PR",
627 <= $z and $z <= 627, "Camuy, PR",
631 <= $z and $z <= 669, "Lares, PR",
636 <= $z and $z <= 683, "San German, PR",
637 <= $z and $z <= 637, "Sabana Grande, PR",
638 <= $z and $z <= 638, "Ciales, PR",
646 <= $z and $z <= 646, "Dorado, PR",
647 <= $z and $z <= 653, "Guanica, PR",
650 <= $z and $z <= 650, "Florida, PR",
656 <= $z and $z <= 785, "Guayanilla, PR",
659 <= $z and $z <= 659, "Hatillo, PR",
660 <= $z and $z <= 660, "Hormigueros, PR",
662 <= $z and $z <= 662, "Isabela, PR",
664 <= $z and $z <= 664, "Jayuya, PR",
667 <= $z and $z <= 667, "Lajas, PR",
670 <= $z and $z <= 670, "Las Marias, PR",
674 <= $z and $z <= 674, "Manati, PR",
676 <= $z and $z <= 676, "Moca, PR",
677 <= $z and $z <= 677, "Rincon, PR",
678 <= $z and $z <= 678, "Quebradillas, PR",
680 <= $z and $z <= 682, "Mayaguez, PR",
685 <= $z and $z <= 685, "San Sebastian, PR",
687 <= $z and $z <= 687, "Morovis, PR",
692 <= $z and $z <= 692, "Vega Alta, PR",
693 <= $z and $z <= 694, "Vega Baja, PR",
698 <= $z and $z <= 698, "Yauco, PR",
703 <= $z and $z <= 703, "Aguas Buenas, PR",
704 <= $z and $z <= 784, "Guayama, PR",
705 <= $z and $z <= 786, "Aibonito, PR",
707 <= $z and $z <= 707, "Maunabo, PR",
714 <= $z and $z <= 714, "Arroyo, PR",
715 <= $z and $z <= 780, "Ponce, PR",
718 <= $z and $z <= 744, "Naguabo, PR",
719 <= $z and $z <= 719, "Naranjito, PR",
720 <= $z and $z <= 720, "Orocovis, PR",
721 <= $z and $z <= 745, "Rio Grande, PR",
723 <= $z and $z <= 723, "Patillas, PR",
725 <= $z and $z <= 727, "Caguas, PR",
729 <= $z and $z <= 729, "Canovanas, PR",
735 <= $z and $z <= 742, "Ceiba, PR",
736 <= $z and $z <= 737, "Cayey, PR",
738 <= $z and $z <= 740, "Fajardo, PR",
739 <= $z and $z <= 739, "Cidra, PR",
741 <= $z and $z <= 792, "Humacao, PR",
751 <= $z and $z <= 751, "Salinas, PR",
754 <= $z and $z <= 754, "San Lorenzo, PR",
757 <= $z and $z <= 757, "Santa Isabel, PR",
765 <= $z and $z <= 765, "Vieques, PR",
766 <= $z and $z <= 766, "Villalba, PR",
767 <= $z and $z <= 767, "Yabucoa, PR",
769 <= $z and $z <= 769, "Coamo, PR",
771 <= $z and $z <= 771, "Las Piedras, PR",
772 <= $z and $z <= 772, "Loiza, PR",
773 <= $z and $z <= 773, "Luquillo, PR",
775 <= $z and $z <= 775, "Culebra, PR",
777 <= $z and $z <= 777, "Juncos, PR",
778 <= $z and $z <= 778, "Gurabo, PR",
782 <= $z and $z <= 782, "Comerio, PR",
783 <= $z and $z <= 783, "Corozal, PR",
794 <= $z and $z <= 794, "Barranquitas, PR",
795 <= $z and $z <= 795, "Juana Diaz, PR",
801 <= $z and $z <= 805, "Saint Thomas, VI",
820 <= $z and $z <= 851, "Saint Croix, VI",
830 <= $z and $z <= 831, "Saint John, VI",
901 <= $z and $z <= 982, "San Juan, PR",
934 <= $z and $z <= 961, "Bayamon, PR",
949 <= $z and $z <= 952, "Toa Baja, PR",
953 <= $z and $z <= 954, "Toa Alta, PR",
962 <= $z and $z <= 963, "Catano, PR",
965 <= $z and $z <= 971, "Guaynabo, PR",
976 <= $z and $z <= 978, "Trujillo Alto, PR",
983 <= $z and $z <= 988, "Carolina, PR",
1001 <= $z and $z <= 1521, "Hampden, MA",
1002 <= $z and $z <= 1243, "Hampshire, MA",
1005 <= $z and $z <= 1772, "Worcester, MA",
1029 <= $z and $z <= 1343, "Berkshire, MA",
1054 <= $z and $z <= 1380, "Franklin, MA",
1431 <= $z and $z <= 2495, "Middlesex, MA",
1810 <= $z and $z <= 5544, "Essex, MA",
2018 <= $z and $z <= 2770, "Plymouth, MA",
2019 <= $z and $z <= 2762, "Norfolk, MA",
2031 <= $z and $z <= 2791, "Bristol, MA",
2101 <= $z and $z <= 2297, "Suffolk, MA",
2532 <= $z and $z <= 2675, "Barnstable, MA",
2535 <= $z and $z <= 2713, "Dukes, MA",
2554 <= $z and $z <= 2584, "Nantucket, MA",
2801 <= $z and $z <= 2878, "Newport, RI",
2802 <= $z and $z <= 2940, "Providence, RI",
2804 <= $z and $z <= 2898, "Washington, RI",
2806 <= $z and $z <= 2885, "Bristol, RI",
2816 <= $z and $z <= 2893, "Kent, RI",
3031 <= $z and $z <= 3468, "Hillsborough, NH",
3032 <= $z and $z <= 3885, "Rockingham, NH",
3046 <= $z and $z <= 3307, "Merrimack, NH",
3215 <= $z and $z <= 3785, "Grafton, NH",
3218 <= $z and $z <= 3837, "Belknap, NH",
3227 <= $z and $z <= 3897, "Carroll, NH",
3280 <= $z and $z <= 3782, "Sullivan, NH",
3431 <= $z and $z <= 3609, "Cheshire, NH",
3570 <= $z and $z <= 3598, "Coos, NH",
3805 <= $z and $z <= 3884, "Strafford, NH",
3901 <= $z and $z <= 4095, "York, ME",
4003 <= $z and $z <= 4260, "Cumberland, ME",
4008 <= $z and $z <= 4579, "Sagadahoc, ME",
4010 <= $z and $z <= 4292, "Oxford, ME",
4210 <= $z and $z <= 4291, "Androscoggin, ME",
4225 <= $z and $z <= 4992, "Franklin, ME",
4259 <= $z and $z <= 4989, "Kennebec, ME",
4341 <= $z and $z <= 4852, "Lincoln, ME",
4354 <= $z and $z <= 4988, "Waldo, ME",
4401 <= $z and $z <= 4969, "Penobscot, ME",
4406 <= $z and $z <= 4485, "Piscataquis, ME",
4408 <= $z and $z <= 4693, "Hancock, ME",
4413 <= $z and $z <= 4694, "Washington, ME",
4471 <= $z and $z <= 4788, "Aroostook, ME",
4478 <= $z and $z <= 4985, "Somerset, ME",
4547 <= $z and $z <= 4865, "Knox, ME",
5001 <= $z and $z <= 5772, "Windsor, VT",
5033 <= $z and $z <= 5679, "Orange, VT",
5042 <= $z and $z <= 5873, "Caledonia, VT",
5101 <= $z and $z <= 5363, "Windham, VT",
5152 <= $z and $z <= 5776, "Bennington, VT",
5401 <= $z and $z <= 5495, "Chittenden, VT",
5440 <= $z and $z <= 5486, "Grand Isle, VT",
5441 <= $z and $z <= 5488, "Franklin, VT",
5442 <= $z and $z <= 5680, "Lamoille, VT",
5443 <= $z and $z <= 5778, "Addison, VT",
5601 <= $z and $z <= 5682, "Washington, VT",
5701 <= $z and $z <= 5777, "Rutland, VT",
5820 <= $z and $z <= 5875, "Orleans, VT",
5824 <= $z and $z <= 5907, "Essex, VT",
6001 <= $z and $z <= 6489, "Hartford, CT",
6018 <= $z and $z <= 6798, "Litchfield, CT",
6029 <= $z and $z <= 6279, "Tolland, CT",
6226 <= $z and $z <= 6387, "Windham, CT",
6249 <= $z and $z <= 6474, "New London, CT",
6401 <= $z and $z <= 6770, "New Haven, CT",
6404 <= $z and $z <= 6928, "Fairfield, CT",
6409 <= $z and $z <= 6498, "Middlesex, CT",
7001 <= $z and $z <= 8989, "Middlesex, NJ",
7002 <= $z and $z <= 7399, "Hudson, NJ",
7003 <= $z and $z <= 7199, "Essex, NJ",
7005 <= $z and $z <= 7999, "Morris, NJ",
7010 <= $z and $z <= 7677, "Bergen, NJ",
7011 <= $z and $z <= 7544, "Passaic, NJ",
7016 <= $z and $z <= 7974, "Union, NJ",
7059 <= $z and $z <= 8896, "Somerset, NJ",
7416 <= $z and $z <= 7890, "Sussex, NJ",
7701 <= $z and $z <= 8750, "Monmouth, NJ",
7820 <= $z and $z <= 8886, "Warren, NJ",
7830 <= $z and $z <= 8889, "Hunterdon, NJ",
8001 <= $z and $z <= 8347, "Salem, NJ",
8002 <= $z and $z <= 8110, "Camden, NJ",
8005 <= $z and $z <= 8759, "Ocean, NJ",
8010 <= $z and $z <= 8641, "Burlington, NJ",
8014 <= $z and $z <= 8344, "Gloucester, NJ",
8037 <= $z and $z <= 8406, "Atlantic, NJ",
8202 <= $z and $z <= 8270, "Cape May, NJ",
8302 <= $z and $z <= 8362, "Cumberland, NJ",
8520 <= $z and $z <= 8695, "Mercer, NJ",
9007 <= $z and $z <= 9899, "undefined, AE",
10001 <= $z and $z <= 10292, "New York, NY",
10301 <= $z and $z <= 10314, "Richmond, NY",
10451 <= $z and $z <= 10499, "Bronx, NY",
10501 <= $z and $z <= 10805, "Westchester, NY",
10509 <= $z and $z <= 12563, "Putnam, NY",
10901 <= $z and $z <= 10995, "Rockland, NY",
10910 <= $z and $z <= 12780, "Orange, NY",
11001 <= $z and $z <= 11855, "Nassau, NY",
11004 <= $z and $z <= 11697, "Queens, NY",
11201 <= $z and $z <= 11256, "Kings, NY",
12007 <= $z and $z <= 12469, "Albany, NY",
12008 <= $z and $z <= 12345, "Schenectady, NY",
12010 <= $z and $z <= 13452, "Montgomery, NY",
12015 <= $z and $z <= 12496, "Greene, NY",
12017 <= $z and $z <= 12593, "Columbia, NY",
12018 <= $z and $z <= 12198, "Rensselaer, NY",
12019 <= $z and $z <= 12884, "Saratoga, NY",
12025 <= $z and $z <= 13470, "Fulton, NY",
12031 <= $z and $z <= 13459, "Schoharie, NY",
12057 <= $z and $z <= 12887, "Washington, NY",
12064 <= $z and $z <= 13861, "Otsego, NY",
12108 <= $z and $z <= 13436, "Hamilton, NY",
12167 <= $z and $z <= 13860, "Delaware, NY",
12401 <= $z and $z <= 12782, "Ulster, NY",
12501 <= $z and $z <= 12604, "Dutchess, NY",
12701 <= $z and $z <= 12792, "Sullivan, NY",
12801 <= $z and $z <= 12886, "Warren, NY",
12851 <= $z and $z <= 12998, "Essex, NY",
12901 <= $z and $z <= 12992, "Clinton, NY",
12914 <= $z and $z <= 13655, "Franklin, NY",
12922 <= $z and $z <= 13699, "Saint Lawrence, NY",
13020 <= $z and $z <= 13290, "Onondaga, NY",
13021 <= $z and $z <= 13166, "Cayuga, NY",
13028 <= $z and $z <= 13493, "Oswego, NY",
13032 <= $z and $z <= 13484, "Madison, NY",
13040 <= $z and $z <= 13863, "Cortland, NY",
13053 <= $z and $z <= 14886, "Tompkins, NY",
13054 <= $z and $z <= 13599, "Oneida, NY",
13065 <= $z and $z <= 14860, "Seneca, NY",
13124 <= $z and $z <= 13844, "Chenango, NY",
13143 <= $z and $z <= 14590, "Wayne, NY",
13305 <= $z and $z <= 13648, "Lewis, NY",
13324 <= $z and $z <= 13491, "Herkimer, NY",
13601 <= $z and $z <= 13693, "Jefferson, NY",
13732 <= $z and $z <= 14892, "Tioga, NY",
13737 <= $z and $z <= 13905, "Broome, NY",
14001 <= $z and $z <= 14280, "Erie, NY",
14003 <= $z and $z <= 14557, "Genesee, NY",
14008 <= $z and $z <= 14305, "Niagara, NY",
14009 <= $z and $z <= 14591, "Wyoming, NY",
14029 <= $z and $z <= 14897, "Allegany, NY",
14041 <= $z and $z <= 14788, "Cattaraugus, NY",
14048 <= $z and $z <= 14787, "Chautauqua, NY",
14098 <= $z and $z <= 14571, "Orleans, NY",
14410 <= $z and $z <= 14694, "Monroe, NY",
14414 <= $z and $z <= 14846, "Livingston, NY",
14415 <= $z and $z <= 14878, "Yates, NY",
14424 <= $z and $z <= 14585, "Ontario, NY",
14529 <= $z and $z <= 14898, "Steuben, NY",
14805 <= $z and $z <= 14893, "Schuyler, NY",
14814 <= $z and $z <= 14925, "Chemung, NY",
15001 <= $z and $z <= 16141, "Beaver, PA",
15004 <= $z and $z <= 15483, "Washington, PA",
15006 <= $z and $z <= 15295, "Allegheny, PA",
15012 <= $z and $z <= 15631, "Fayette, PA",
15062 <= $z and $z <= 15954, "Westmoreland, PA",
15310 <= $z and $z <= 15380, "Greene, PA",
15411 <= $z and $z <= 15963, "Somerset, PA",
15521 <= $z and $z <= 17211, "Bedford, PA",
15536 <= $z and $z <= 17267, "Fulton, PA",
15630 <= $z and $z <= 16263, "Armstrong, PA",
15681 <= $z and $z <= 16256, "Indiana, PA",
15711 <= $z and $z <= 15865, "Jefferson, PA",
15714 <= $z and $z <= 16699, "Cambria, PA",
15721 <= $z and $z <= 16881, "Clearfield, PA",
15821 <= $z and $z <= 16734, "Elk, PA",
15828 <= $z and $z <= 16370, "Forest, PA",
15832 <= $z and $z <= 15861, "Cameron, PA",
16001 <= $z and $z <= 16066, "Butler, PA",
16028 <= $z and $z <= 16375, "Clarion, PA",
16101 <= $z and $z <= 16172, "Lawrence, PA",
16110 <= $z and $z <= 16440, "Crawford, PA",
16113 <= $z and $z <= 16311, "Mercer, PA",
16301 <= $z and $z <= 16374, "Venango, PA",
16312 <= $z and $z <= 16436, "Warren, PA",
16333 <= $z and $z <= 16751, "Mckean, PA",
16401 <= $z and $z <= 16565, "Erie, PA",
16601 <= $z and $z <= 16693, "Blair, PA",
16611 <= $z and $z <= 17264, "Huntingdon, PA",
16677 <= $z and $z <= 16882, "Centre, PA",
16720 <= $z and $z <= 17729, "Potter, PA",
16822 <= $z and $z <= 17779, "Clinton, PA",
16901 <= $z and $z <= 17765, "Tioga, PA",
16910 <= $z and $z <= 18854, "Bradford, PA",
17001 <= $z and $z <= 17266, "Cumberland, PA",
17002 <= $z and $z <= 17099, "Mifflin, PA",
17003 <= $z and $z <= 17088, "Lebanon, PA",
17005 <= $z and $z <= 17177, "Dauphin, PA",
17006 <= $z and $z <= 17090, "Perry, PA",
17014 <= $z and $z <= 17094, "Juniata, PA",
17017 <= $z and $z <= 17881, "Northumberland, PA",
17019 <= $z and $z <= 17415, "York, PA",
17022 <= $z and $z <= 19501, "Lancaster, PA",
17201 <= $z and $z <= 17272, "Franklin, PA",
17301 <= $z and $z <= 17375, "Adams, PA",
17701 <= $z and $z <= 17776, "Lycoming, PA",
17731 <= $z and $z <= 18632, "Sullivan, PA",
17810 <= $z and $z <= 17889, "Union, PA",
17812 <= $z and $z <= 17882, "Snyder, PA",
17814 <= $z and $z <= 18631, "Columbia, PA",
17821 <= $z and $z <= 17884, "Montour, PA",
17901 <= $z and $z <= 19549, "Schuylkill, PA",
18001 <= $z and $z <= 18351, "Northampton, PA",
18011 <= $z and $z <= 18195, "Lehigh, PA",
18012 <= $z and $z <= 18624, "Carbon, PA",
18039 <= $z and $z <= 19067, "Bucks, PA",
18041 <= $z and $z <= 19525, "Montgomery, PA",
18056 <= $z and $z <= 19640, "Berks, PA",
18058 <= $z and $z <= 18610, "Monroe, PA",
18201 <= $z and $z <= 18774, "Luzerne, PA",
18324 <= $z and $z <= 18464, "Pike, PA",
18401 <= $z and $z <= 18473, "Wayne, PA",
18403 <= $z and $z <= 18653, "Lackawanna, PA",
18413 <= $z and $z <= 18847, "Susquehanna, PA",
18419 <= $z and $z <= 18657, "Wyoming, PA",
19003 <= $z and $z <= 19373, "Delaware, PA",
19019 <= $z and $z <= 19255, "Philadelphia, PA",
19301 <= $z and $z <= 19520, "Chester, PA",
19415 <= $z and $z <= 19415, "undefined, PA",
19701 <= $z and $z <= 19899, "New Castle, DE",
19901 <= $z and $z <= 19980, "Kent, DE",
19930 <= $z and $z <= 19975, "Sussex, DE",
20001 <= $z and $z <= 20599, "District Of Columbia, DC",
20101 <= $z and $z <= 22093, "Loudoun, VA",
20106 <= $z and $z <= 22749, "Rappahannock, VA",
20108 <= $z and $z <= 20110, "Manassas City, VA",
20111 <= $z and $z <= 20113, "Manassas Park City, VA",
20115 <= $z and $z <= 22742, "Fauquier, VA",
20120 <= $z and $z <= 22321, "Fairfax, VA",
20136 <= $z and $z <= 22195, "Prince William, VA",
20601 <= $z and $z <= 20695, "Charles, MD",
20606 <= $z and $z <= 20692, "Saint Marys, MD",
20607 <= $z and $z <= 20799, "Prince Georges, MD",
20610 <= $z and $z <= 20754, "Calvert, MD",
20701 <= $z and $z <= 21794, "Howard, MD",
20711 <= $z and $z <= 21412, "Anne Arundel, MD",
20812 <= $z and $z <= 20997, "Montgomery, MD",
21001 <= $z and $z <= 21161, "Harford, MD",
21013 <= $z and $z <= 21286, "Baltimore, MD",
21048 <= $z and $z <= 21797, "Carroll, MD",
21201 <= $z and $z <= 21298, "Baltimore City, MD",
21501 <= $z and $z <= 21766, "Allegany, MD",
21520 <= $z and $z <= 21561, "Garrett, MD",
21601 <= $z and $z <= 21679, "Talbot, MD",
21607 <= $z and $z <= 21690, "Queen Annes, MD",
21609 <= $z and $z <= 21688, "Caroline, MD",
21610 <= $z and $z <= 21678, "Kent, MD",
21613 <= $z and $z <= 21869, "Dorchester, MD",
21701 <= $z and $z <= 21798, "Frederick, MD",
21711 <= $z and $z <= 21795, "Washington, MD",
21801 <= $z and $z <= 21875, "Wicomico, MD",
21811 <= $z and $z <= 21872, "Worcester, MD",
21817 <= $z and $z <= 21890, "Somerset, MD",
21901 <= $z and $z <= 21930, "Cecil, MD",
22030 <= $z and $z <= 22038, "Fairfax City, VA",
22040 <= $z and $z <= 22046, "Falls Church City, VA",
22201 <= $z and $z <= 22246, "Arlington, VA",
22301 <= $z and $z <= 22336, "Alexandria City, VA",
22401 <= $z and $z <= 22404, "Fredericksburg City, VA",
22403 <= $z and $z <= 22555, "Stafford, VA",
22407 <= $z and $z <= 22565, "Spotsylvania, VA",
22427 <= $z and $z <= 22580, "Caroline, VA",
22432 <= $z and $z <= 22579, "Northumberland, VA",
22433 <= $z and $z <= 22972, "Orange, VA",
22436 <= $z and $z <= 23115, "Essex, VA",
22442 <= $z and $z <= 22581, "Westmoreland, VA",
22448 <= $z and $z <= 22547, "King George, VA",
22460 <= $z and $z <= 22572, "Richmond, VA",
22480 <= $z and $z <= 22578, "Lancaster, VA",
22601 <= $z and $z <= 22604, "Winchester City, VA",
22602 <= $z and $z <= 22656, "Frederick, VA",
22610 <= $z and $z <= 22649, "Warren, VA",
22611 <= $z and $z <= 22663, "Clarke, VA",
22626 <= $z and $z <= 22847, "Shenandoah, VA",
22650 <= $z and $z <= 22851, "Page, VA",
22701 <= $z and $z <= 22741, "Culpeper, VA",
22709 <= $z and $z <= 22989, "Madison, VA",
22801 <= $z and $z <= 22807, "Harrisonburg City, VA",
22802 <= $z and $z <= 24471, "Rockingham, VA",
22843 <= $z and $z <= 24486, "Augusta, VA",
22901 <= $z and $z <= 24590, "Albemarle, VA",
22902 <= $z and $z <= 22910, "Charlottesville City, VA",
22920 <= $z and $z <= 24599, "Nelson, VA",
22935 <= $z and $z <= 22973, "Greene, VA",
22963 <= $z and $z <= 23084, "Fluvanna, VA",
22980 <= $z and $z <= 22980, "Waynesboro City, VA",
23001 <= $z and $z <= 23191, "Gloucester, VA",
23002 <= $z and $z <= 23105, "Amelia, VA",
23004 <= $z and $z <= 23936, "Buckingham, VA",
23005 <= $z and $z <= 23192, "Hanover, VA",
23009 <= $z and $z <= 23181, "King William, VA",
23011 <= $z and $z <= 23141, "New Kent, VA",
23014 <= $z and $z <= 23238, "Goochland, VA",
23021 <= $z and $z <= 23163, "Mathews, VA",
23023 <= $z and $z <= 23177, "King And Queen, VA",
23024 <= $z and $z <= 23170, "Louisa, VA",
23027 <= $z and $z <= 23040, "Cumberland, VA",
23030 <= $z and $z <= 23147, "Charles City, VA",
23031 <= $z and $z <= 23180, "Middlesex, VA",
23058 <= $z and $z <= 23294, "Henrico, VA",
23081 <= $z and $z <= 23188, "James City, VA",
23090 <= $z and $z <= 23696, "York, VA",
23101 <= $z and $z <= 23139, "Powhatan, VA",
23112 <= $z and $z <= 23838, "Chesterfield, VA",
23173 <= $z and $z <= 23298, "Richmond City, VA",
23186 <= $z and $z <= 23187, "Williamsburg City, VA",
23301 <= $z and $z <= 23488, "Accomack, VA",
23304 <= $z and $z <= 23898, "Isle Of Wight, VA",
23307 <= $z and $z <= 23486, "Northampton, VA",
23320 <= $z and $z <= 23328, "Chesapeake City, VA",
23432 <= $z and $z <= 23439, "Suffolk City, VA",
23450 <= $z and $z <= 23521, "Virginia Beach City, VA",
23501 <= $z and $z <= 23551, "Norfolk City, VA",
23601 <= $z and $z <= 23628, "Newport News City, VA",
23630 <= $z and $z <= 23681, "Hampton City, VA",
23662 <= $z and $z <= 23662, "Poquoson City, VA",
23701 <= $z and $z <= 23709, "Portsmouth City, VA",
23801 <= $z and $z <= 23875, "Prince George, VA",
23803 <= $z and $z <= 23806, "Petersburg City, VA",
23821 <= $z and $z <= 23920, "Brunswick, VA",
23822 <= $z and $z <= 23894, "Dinwiddie, VA",
23824 <= $z and $z <= 23955, "Nottoway, VA",
23827 <= $z and $z <= 23878, "Southampton, VA",
23834 <= $z and $z <= 23834, "Colonial Heights City, VA",
23839 <= $z and $z <= 23899, "Surry, VA",
23847 <= $z and $z <= 23847, "Emporia City, VA",
23851 <= $z and $z <= 23851, "Franklin City, VA",
23860 <= $z and $z <= 23860, "Hopewell City, VA",
23867 <= $z and $z <= 23897, "Sussex, VA",
23870 <= $z and $z <= 23879, "Greensville, VA",
23901 <= $z and $z <= 23966, "Prince Edward, VA",
23915 <= $z and $z <= 24580, "Mecklenburg, VA",
23923 <= $z and $z <= 23976, "Charlotte, VA",
23938 <= $z and $z <= 23974, "Lunenburg, VA",
23939 <= $z and $z <= 24593, "Appomattox, VA",
24001 <= $z and $z <= 24048, "Roanoke City, VA",
24018 <= $z and $z <= 24179, "Roanoke, VA",
24019 <= $z and $z <= 24438, "Botetourt, VA",
24023 <= $z and $z <= 24162, "Montgomery, VA",
24053 <= $z and $z <= 24185, "Patrick, VA",
24054 <= $z and $z <= 24168, "Henry, VA",
24058 <= $z and $z <= 24347, "Pulaski, VA",
24065 <= $z and $z <= 24184, "Franklin, VA",
24069 <= $z and $z <= 24594, "Pittsylvania, VA",
24072 <= $z and $z <= 24380, "Floyd, VA",
24086 <= $z and $z <= 24167, "Giles, VA",
24095 <= $z and $z <= 24570, "Bedford, VA",
24112 <= $z and $z <= 24115, "Martinsville City, VA",
24127 <= $z and $z <= 24131, "Craig, VA",
24141 <= $z and $z <= 24143, "Radford, VA",
24153 <= $z and $z <= 24157, "Salem, VA",
24201 <= $z and $z <= 24209, "Bristol, VA",
24210 <= $z and $z <= 24361, "Washington, VA",
24215 <= $z and $z <= 24293, "Wise, VA",
24217 <= $z and $z <= 24607, "Dickenson, VA",
24218 <= $z and $z <= 24282, "Lee, VA",
24224 <= $z and $z <= 24649, "Russell, VA",
24239 <= $z and $z <= 24658, "Buchanan, VA",
24244 <= $z and $z <= 24290, "Scott, VA",
24273 <= $z and $z <= 24273, "Norton City, VA",
24292 <= $z and $z <= 24379, "Grayson, VA",
24311 <= $z and $z <= 24375, "Smyth, VA",
24312 <= $z and $z <= 24382, "Wythe, VA",
24314 <= $z and $z <= 24366, "Bland, VA",
24317 <= $z and $z <= 24381, "Carroll, VA",
24333 <= $z and $z <= 24333, "Galax City, VA",
24377 <= $z and $z <= 24651, "Tazewell, VA",
24401 <= $z and $z <= 24402, "Staunton City, VA",
24412 <= $z and $z <= 24487, "Bath, VA",
24413 <= $z and $z <= 24468, "Highland, VA",
24415 <= $z and $z <= 24579, "Rockbridge, VA",
24416 <= $z and $z <= 24416, "Buena Vista City, VA",
24422 <= $z and $z <= 24422, "Clifton Forge City, VA",
24426 <= $z and $z <= 24426, "Covington City, VA",
24448 <= $z and $z <= 24474, "Alleghany, VA",
24450 <= $z and $z <= 24450, "Lexington City, VA",
24501 <= $z and $z <= 24515, "Lynchburg City, VA",
24512 <= $z and $z <= 24588, "Campbell, VA",
24520 <= $z and $z <= 24598, "Halifax, VA",
24521 <= $z and $z <= 24595, "Amherst, VA",
24523 <= $z and $z <= 24523, "Bedford City, VA",
24540 <= $z and $z <= 24544, "Danville City, VA",
24701 <= $z and $z <= 25971, "Mercer, WV",
24716 <= $z and $z <= 25943, "Wyoming, WV",
24801 <= $z and $z <= 24899, "Mcdowell, WV",
24851 <= $z and $z <= 25697, "Mingo, WV",
24901 <= $z and $z <= 25984, "Greenbrier, WV",
24915 <= $z and $z <= 26291, "Pocahontas, WV",
24918 <= $z and $z <= 24993, "Monroe, WV",
24919 <= $z and $z <= 25988, "Summers, WV",
25002 <= $z and $z <= 26680, "Fayette, WV",
25003 <= $z and $z <= 25396, "Kanawha, WV",
25004 <= $z and $z <= 25989, "Raleigh, WV",
25005 <= $z and $z <= 25286, "Roane, WV",
25009 <= $z and $z <= 25529, "Boone, WV",
25011 <= $z and $z <= 25569, "Putnam, WV",
25018 <= $z and $z <= 26617, "Clay, WV",
25022 <= $z and $z <= 25654, "Logan, WV",
25059 <= $z and $z <= 26691, "Nicholas, WV",
25095 <= $z and $z <= 25550, "Mason, WV",
25231 <= $z and $z <= 26173, "Jackson, WV",
25234 <= $z and $z <= 26151, "Calhoun, WV",
25258 <= $z and $z <= 26638, "Gilmer, WV",
25401 <= $z and $z <= 25440, "Berkeley, WV",
25410 <= $z and $z <= 25446, "Jefferson, WV",
25411 <= $z and $z <= 25434, "Morgan, WV",
25431 <= $z and $z <= 26865, "Hampshire, WV",
25501 <= $z and $z <= 25573, "Lincoln, WV",
25504 <= $z and $z <= 25779, "Cabell, WV",
25507 <= $z and $z <= 25709, "Wayne, WV",
26003 <= $z and $z <= 26074, "Ohio, WV",
26030 <= $z and $z <= 26075, "Brooke, WV",
26031 <= $z and $z <= 26055, "Marshall, WV",
26034 <= $z and $z <= 26062, "Hancock, WV",
26101 <= $z and $z <= 26187, "Wood, WV",
26134 <= $z and $z <= 26170, "Pleasants, WV",
26135 <= $z and $z <= 26434, "Tyler, WV",
26138 <= $z and $z <= 26160, "Wirt, WV",
26148 <= $z and $z <= 26421, "Ritchie, WV",
26155 <= $z and $z <= 26581, "Wetzel, WV",
26201 <= $z and $z <= 26237, "Upshur, WV",
26203 <= $z and $z <= 26298, "Webster, WV",
26224 <= $z and $z <= 26296, "Randolph, WV",
26238 <= $z and $z <= 26416, "Barbour, WV",
26260 <= $z and $z <= 26292, "Tucker, WV",
26301 <= $z and $z <= 26568, "Harrison, WV",
26321 <= $z and $z <= 26452, "Lewis, WV",
26328 <= $z and $z <= 26456, "Doddridge, WV",
26335 <= $z and $z <= 26641, "Braxton, WV",