Geographic Fragmentation: How Far Do Area Codes Reach?

Analysis of county coverage across US area codes. Discover which area codes span the most counties, which are hyper-local, and how geographic fragmentation correlates with population density.

605— spans 79 counties across 7 states
Published: Updated: Sources & Methodology

Key Findings

79
Counties in the most fragmented code (605)

605 spans 7 states: IA, MN, MT, ND, NE, SD, WY

21
Single-county (hyper-local) area codes

6% of all codes cover just one county

63
Multi-state area codes

Codes that cross state boundaries

The 605 area code is the most geographically fragmented in the US, covering 79 counties across 7 states (IA, MN, MT, ND, NE, SD, WY). This extreme fragmentation reflects the sparse population density of the Great Plains — a single area code must cover vast territory to serve enough subscribers. In contrast, area code 213 serves just 2,400,544 people in a single county.

Urban vs Rural Patterns

Urban Sprawl (37 codes)

Area codes with high average population per county (over 500k) that still span multiple counties — dense suburban/metro regions.

214/469/945/972(overlay)12 counties, avg 552k pop
28110 counties, avg 810k pop
3476 counties, avg 1177k pop
9296 counties, avg 1177k pop
9514 counties, avg 527k pop
2013 counties, avg 528k pop

Rural Sprawl (12 codes)

Area codes that span many counties with low average population per county — sparse, rural regions.

60579 counties, avg 20k pop
62063 counties, avg 18k pop
70163 counties, avg 17k pop
78563 counties, avg 23k pop
30859 counties, avg 13k pop
58053 counties, avg 25k pop

Key insight: Geographic fragmentation is inversely correlated with population density. Urban area codes like 214 cover 12 counties but serve 6.6M people — while rural codes like 906 span 15 counties but serve only 349k people.

All Area Codes

Browse all 326 area codes ranked by county coverage. Click any code to view its detail page.

Code ↕State(s) ↕Type ↕Counties ▼Population ↕Avg Pop/County ↕
605IA, MN, MT, ND, NE, SD, WYgeographic791.6M20k
706AL, GA, TNgeographic704.1M59k
762(of 706)AL, GA, TNoverlay704.1M59k
620KSsplit631.1M18k
701MN, MT, ND, SDgeographic631.1M17k
785KS, NEsplit631.4M23k
870AR, LA, MO, OKgeographic632.0M31k
327(of 870)AR, LA, MO, OKoverlay632.0M31k
308CO, KS, NE, SDgeographic59741k13k
402KS, NE, SDgeographic592.2M37k
406ID, MT, NDgeographic591.6M27k
531(of 402)KS, NE, SDoverlay592.2M37k
540VA, WVgeographic583.3M58k
573IL, MOgeographic582.3M39k
235(of 573)IL, MOoverlay582.3M39k
826(of 540)VA, WVoverlay583.3M58k
304WVgeographic552.6M48k
681(of 304)WVoverlay552.6M48k
580OK, TXsplit531.3M25k
606KY, TNgeographic531.7M31k
270KYgeographic502.3M47k
364(of 270)KYoverlay502.3M47k
806TXgeographic491.5M30k
229GAsplit481.5M31k
641IAsplit48827k17k
662AL, AR, MSgeographic482.2M45k
471(of 662)AL, AR, MSoverlay482.2M45k
208ID, UT, WA, WYgeographic472.8M60k
986(of 208)ID, UT, WA, WYoverlay472.8M60k
601MSgeographic452.9M64k
769(of 601)MSoverlay452.9M64k
217ILgeographic441.5M34k
660MOsplit44729k17k
765INsplit442.3M53k
447(of 217)ILoverlay441.5M34k
931KY, TNsplit432.5M58k
220(of 740)OHoverlay432.8M65k
534(of 715)MI, WIoverlay432.2M52k
618ILgeographic421.8M43k
812INgeographic422.7M64k
730(of 618)ILoverlay421.8M43k
930(of 812)INoverlay422.7M64k
325TXsplit40874k22k
712IA, MN, MO, NE, SDgeographic39868k22k
507IA, MN, SDgeographic381.4M37k
970CO, NE, NM, UT, WYgeographic381.8M46k
430(of 903)AR, TXoverlay382.4M62k
748(of 970)CO, NE, NM, UT, WYoverlay381.8M46k
924(of 507)IA, MN, SDoverlay381.4M37k
423TN, VAgeographic372.4M64k
729(of 423)TN, VAoverlay372.4M64k
830TXsplit361.7M47k
334AL, GAgeographic352.0M58k
483(of 334)AL, GAoverlay352.0M58k
218MN, NDgeographic341.3M39k
252NCsplit341.9M56k
419OHgeographic342.6M77k
434VAsplit341.5M43k
478GAsplit341.3M39k
804VAgeographic342.5M74k
458(of 541)ID, NV, ORoverlay342.2M65k
567(of 419)OHoverlay342.6M77k
686(of 804)VAoverlay342.5M74k
320MN, SDsplit33998k30k
417AR, MOgeographic331.9M57k
912GAgeographic331.5M46k
989MIsplit331.6M48k
539(of 918)OKoverlay332.4M72k
565(of 912)GAoverlay331.5M46k
318LAgeographic321.7M53k
457(of 318)LAoverlay321.7M53k
575NM, TXsplit31897k29k
307CO, ID, MT, NE, SD, WYgeographic30689k23k
719CO, NMsplit301.4M46k
859KYsplit301.9M65k
907AKgeographic30791k26k
254TXsplit291.5M51k
435AZ, NV, UT, WYsplit29940k32k
205ALgeographic282.3M82k
256ALgeographic282.4M86k
803SCgeographic282.5M89k
582(of 814)PAoverlay281.7M62k
659(of 205)ALoverlay282.3M82k
839(of 803)SCoverlay282.5M89k
938(of 256)ALoverlay282.4M86k
336NC, VAgeographic273.1M114k
361TXsplit271.2M45k
828NCsplit272.3M83k
936TXsplit271.3M48k
743(of 336)NC, VAoverlay273.1M114k
319IA, MOgeographic261.2M45k
272(of 570)PAoverlay262.2M85k
274(of 920)WIoverlay262.1M81k
326(of 937)OHoverlay262.5M96k
779(of 815)ILoverlay262.6M100k
276VA, WVsplit25763k31k
432TXsplit25813k33k
509ID, OR, WAgeographic252.1M83k
940TXsplit251.1M45k
231MIsplit241.2M49k
309ILgeographic241.2M48k
405OKgeographic242.2M92k
515IAgeographic241.3M54k
572(of 405)OKoverlay242.2M92k
861(of 309)ILoverlay241.2M48k
502KYgeographic232.1M91k
530CA, ORgeographic231.6M71k
608WIgeographic231.7M76k
731KY, MS, TNsplit23904k39k
843SCgeographic232.7M118k
353(of 608)WIoverlay231.7M76k
761(of 502)KYoverlay232.1M91k
837(of 530)CA, ORoverlay231.6M71k
854(of 843)SCoverlay232.7M118k
315NYgeographic222.1M94k
615TNgeographic223.1M140k
629(of 615)TNoverlay223.1M140k
680(of 315)NYoverlay222.1M94k
501ARgeographic211.6M78k
518NYgeographic211.9M92k
757VAgeographic212.3M108k
919NCgeographic214.4M208k
838(of 518)NYoverlay211.9M92k
948(of 757)VAoverlay212.3M108k
984(of 919)NCoverlay214.4M208k
410DE, MDgeographic204.3M217k
607NYgeographic201.1M56k
704NCgeographic203.6M182k
775CA, ID, NVsplit201.1M54k
443(of 410)DE, MDoverlay204.3M217k
472(of 910)NCoverlay202.2M111k
667(of 410)DE, MDoverlay204.3M217k
980(of 704)NCoverlay203.6M182k
360WAgeographic192.8M146k
512TXgeographic193.8M200k
865TNsplit191.7M90k
737(of 512)TXoverlay193.8M200k
352FLsplit182.1M117k
479AR, OKsplit181.4M76k
234(of 330)OHoverlay183.1M172k
448(of 850)FLoverlay181.8M101k
207ME, NHgeographic171.4M82k
260INsplit171.1M66k
563IAsplit17653k38k
864SCgeographic172.3M137k
979TXsplit17842k50k
821(of 864)SCoverlay172.3M137k
337LAsplit161.6M98k
505AZ, NMgeographic161.6M101k
574INsplit161.1M69k
816MOgeographic161.8M110k
863FLsplit161.5M96k
928AZ, NM, UTsplit161.3M82k
223(of 717)PAoverlay162.6M161k
975(of 816)MOoverlay161.8M110k
386FLsplit151.2M78k
906MIgeographic15349k23k
209CAgeographic142.2M155k
303COgeographic145.3M376k
517MIgeographic141.4M102k
724PAgeographic142.1M153k
802VTgeographic14753k54k
350(of 209)CAoverlay142.2M155k
720(of 303)COoverlay145.3M376k
983(of 303)COoverlay145.3M376k
225LAsplit131.1M82k
317INgeographic132.7M205k
585NYsplit131.4M110k
985LAsplit131.3M103k
463(of 317)INoverlay132.7M205k
214TXgeographic126.6M552k
262WIsplit121.6M135k
409TXsplit12762k64k
503ORgeographic123.4M287k
913KSgeographic121.1M90k
227(of 301)MDoverlay123.4M283k
469(of 214)TXoverlay126.6M552k
682(of 817)TXoverlay123.5M288k
945(of 214)TXoverlay126.6M552k
971(of 503)ORoverlay123.4M287k
972(of 214)TXoverlay126.6M552k
269MIsplit111.4M123k
609NJgeographic111.5M138k
369(of 707)CAoverlay111.6M146k
484(of 610)PAoverlay113.5M319k
640(of 609)NJoverlay111.5M138k
835(of 610)PAoverlay113.5M319k
440OHgeographic101.6M159k
559CAgeographic102.2M219k
603NHgeographic101.6M156k
636MOsplit101.3M133k
763MNsplit101.6M161k
810MIsplit101.1M108k
904FLgeographic101.9M191k
281(of 713)TXoverlay108.1M810k
283(of 513)OHoverlay102.2M222k
324(of 904)FLoverlay101.9M191k
329(of 845)NYoverlay101.7M166k
357(of 559)CAoverlay102.2M219k
436(of 440)OHoverlay101.6M159k
571(of 703)VAoverlay103.1M313k
219INgeographic91.1M121k
251ALsplit9864k96k
316KSgeographic9748k83k
616MIgeographic91.5M172k
952MNsplit9997k111k
956TXsplit91.6M176k
508MAgeographic82.2M273k
651MNsplit81.5M184k
716NYgeographic81.5M182k
442(of 760)CAoverlay82.4M306k
624(of 716)NYoverlay81.5M182k
774(of 508)MAoverlay82.2M273k
862(of 973)NJoverlay82.2M280k
210TXgeographic72.4M350k
248MIgeographic71.6M234k
321FLsplit73.3M465k
860CTgeographic71.8M261k
908NJsplit71.3M188k
279(of 916)CAoverlay72.1M304k
380(of 614)OHoverlay72.3M327k
726(of 210)TXoverlay72.4M350k
947(of 248)MIoverlay71.6M234k
959(of 860)CToverlay71.8M261k
215PAgeographic62.9M490k
239FLsplit61.3M223k
401MA, RIgeographic61.2M193k
520AZsplit61.7M290k
732NJgeographic62.3M381k
734MIgeographic61.5M245k
805CAgeographic61.8M293k
856NJsplit61.6M263k
224(of 847)ILoverlay63.0M500k
267(of 215)PAoverlay62.9M490k
331(of 630)ILoverlay62.1M354k
347(of 718)NYoverlay67.1M1.2M
385(of 801)UToverlay62.7M442k
445(of 215)PAoverlay62.9M490k
820(of 805)CAoverlay61.8M293k
848(of 732)NJoverlay62.3M381k
929(of 718)NYoverlay67.1M1.2M
413MAgeographic5884k177k
504LAgeographic5827k165k
661CAsplit51.7M339k
772FLsplit5753k151k
808HIgeographic51.4M289k
339(of 781)MAoverlay51.3M265k
656(of 813)FLoverlay51.9M388k
203CTgeographic41.8M462k
228MSsplit4476k119k
302DE, MDgeographic41.1M278k
412PAgeographic41.3M319k
414WIgeographic41.1M265k
425WAsplit41.4M361k
831CAsplit41.0M251k
901AR, TNgeographic41.2M296k
915NM, TXgeographic4987k247k
925CAsplit41.3M327k
941FLsplit41.2M293k
951CAsplit42.1M527k
351(of 978)MAoverlay41.5M363k
475(of 203)CToverlay41.8M462k
878(of 412)PAoverlay41.3M319k
201NJgeographic31.6M528k
253WAsplit31.4M458k
404GAgeographic31.4M481k
415CAgeographic31.2M386k
617MAgeographic31.5M494k
702CA, NVgeographic32.3M766k
914NYgeographic31.0M343k
341(of 510)CAoverlay31.8M603k
363(of 516)NYoverlay31.5M497k
464(of 708)ILoverlay31.6M522k
470(of 404)GAoverlay31.4M481k
551(of 201)NJoverlay31.6M528k
628(of 415)CAoverlay31.2M386k
678(of 404)GAoverlay31.4M481k
725(of 702)CA, NVoverlay32.3M766k
840(of 909)CAoverlay32.4M812k
857(of 617)MAoverlay31.5M494k
943(of 404)GAoverlay31.4M481k
206WAgeographic21.1M527k
305FLgeographic22.7M1.4M
310CAgeographic21.9M946k
313MIgeographic21.1M540k
314MOgeographic21.3M673k
408CAgeographic21.7M853k
561FLgeographic21.6M785k
562CAsplit21.6M782k
586MIsplit2889k445k
626CAsplit21.4M681k
631NYgeographic21.5M733k
650CAsplit2960k480k
727FLsplit21.2M599k
424(of 310)CAoverlay21.9M946k
557(of 314)MOoverlay21.3M673k
564(of 206)WAoverlay21.1M527k
645(of 305)FLoverlay22.7M1.4M
657(of 714)CAoverlay22.1M1.0M
669(of 408)CAoverlay21.7M853k
679(of 313)MIoverlay21.1M540k
728(of 561)FLoverlay21.6M785k
747(of 818)CAoverlay22.0M1.0M
786(of 305)FLoverlay22.7M1.4M
934(of 631)NYoverlay21.5M733k
202DCgeographic1672k672k
212NYgeographic11.6M1.6M
213CAgeographic12.4M2.4M
216OHgeographic1727k727k
312ILgeographic1293k293k
602AZgeographic1988k988k
612MNgeographic1446k446k
619CAgeographic12.4M2.4M
773ILgeographic12.4M2.4M
949CAsplit1994k994k
323(of 213)CAoverlay12.4M2.4M
332(of 212)NYoverlay11.6M1.6M
480(of 602)AZoverlay1988k988k
623(of 602)AZoverlay1988k988k
646(of 212)NYoverlay11.6M1.6M
738(of 213)CAoverlay12.4M2.4M
754(of 954)FLoverlay11.9M1.9M
771(of 202)DCoverlay1672k672k
858(of 619)CAoverlay12.4M2.4M
872(of 312)ILoverlay1293k293k
917(of 212)NYoverlay11.6M1.6M
Showing 326 of 326 area codes

Methodology

Data source: County boundaries from our proprietary geographic dataset derived from US Census TIGER/Line shapefiles, cross-referenced with NANPA area code assignments.

Coverage: 326 of 376 total US area codes (87%) have county-level geographic data. Puerto Rico and Canadian area codes are excluded.

Population: County population figures are approximate estimates. Actual values may vary slightly from Census Bureau figures.

Multi-state codes: Some area codes serve multiple states (e.g., 605 covers 7 states). The county count includes all counties across all states served.

Overlay codes: Overlay area codes share the same geographic area as their parent codes. For overlay codes, we use the parent's county data to avoid double-counting. This matches the methodology used in our demographics section.

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