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",