Area Code 520
Telephone Central Office Building Pictures

The following are representative examples of telephone central office buildings in Area Code 520 (south/southeastern Arizona).

Click on the pictures below for a larger version.

Ajo	Listing Updated: April 2011 Operating Company: Table Top Telephone Co. CLLI: AJO AZXCDS0 Switch Type: Nokia/Alcatel/Lucent 5ESS Prefixes Served: (520) 387 Notes: Source: Craig L.
Benson "Main"	Listing Updated: December 2009 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: BNSNAZMADS0 Switch Type: Ribbon/Genband/Nortel DMS-10 Prefixes Served: (520) 586 Notes: Source: Craig L.
Benson "St. David"	Listing Updated: December 2009 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: BNSNAZSDDS0 Switch Type: Ribbon/Genband/Nortel DMS-10 Prefixes Served: (520) 720 Notes: Source: Craig L.
Bisbee "Main"	Listing Updated: December 2009 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: BISBAZMARS1 Switch Type: Ribbon/Genband/Nortel RSC Prefixes Served: (520) 432 Notes: Source: Craig L.
Bisbee "Palominas Main"	Listing Updated: August 2010 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: PLMNAZMARS1 Switch Type: Ribbon/Genband/Nortel RSC Prefixes Served: (520) 366 Notes: Source: Craig L.
Bowie	Listing Updated: February 2012 Operating Company: Valley Telephone Cooperative CLLI: (was BOWIAZXCDS0) Switch Type: Ribbon/Genband/Nortel DMS-10 Prefixes Served: (520) 847 Notes: Source: Craig L.
Casa Grande "Arizona City"	Listing Updated: November 2010 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: AZCYAZ03RS1 Switch Type: Ribbon/Genband/Nortel RSC Prefixes Served: (520) 494 Notes: Source: Craig L.
Casa Grande "Main" Photo 2	Listing Updated: April 2021 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: CSGRAZMADS0 Switch Type: Ribbon/Genband/Nortel DMS-100 Prefixes Served: (520) 316, 374, 421, 423, 426, 836, 858, 876 Notes: Photo 2 is the original by Craig L. in October 2009. Current picture source: GSV.
Casa Grande "Coolidge"	Listing Updated: April 2010 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: CLDGAZMARS1 Switch Type: Ribbon/Genband/Nortel RSC Prefixes Served: (520) 723 Notes: Source: Craig L.
Casa Grande "Eloy"	Listing Updated: December 2009 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: ELOYAZ01RS1 Switch Type: Ribbon/Genband/Nortel RSC Prefixes Served: (520) 464, 466 Notes: Source: Craig L.
Casa Grande "Florence"	Listing Updated: August 2010 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: FLRNAZMARS1 Switch Type: Ribbon/Genband/Nortel RSC Prefixes Served: (520) 866, 868 Notes: Source: Craig L.
Casa Grande "Maricopa"	Listing Updated: October 2009 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: MRCPAZMADS0 Switch Type: Digital Switch (unknown type) Prefixes Served: (520) 568 Notes: Source: Craig L.
Casa Grande "Stanfield"	Listing Updated: August 2010 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: STFDAZMARS1 Switch Type: Ribbon/Genband/Nortel RSC Prefixes Served: (520) 424 Notes: Source: Craig L.
Cascabel	Listing Updated: September 2011 Operating Company: Midvale Telephone Company CLLI: CSELAZXCDS0 Switch Type: Redcom MDX 10K Prefixes Served: (520) 212 Notes: Source: Craig L. This area did not have telephone service until 1993.
Douglas	Listing Updated: May 2010 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: DGLSAZMARS1 Switch Type: Ribbon/Genband/Nortel RSC Prefixes Served: (520) 364, 368, 805 Notes: Source: Craig L.
Elfrida	Listing Updated: November 2011 Operating Company: Copper Valley Telephone CLLI: (was ELFRAZXCDS0) Switch Type: Ribbon/Genband/Nortel DMS-10 Prefixes Served: (520) 642 Notes: Source: Craig L.
Hayden	Listing Updated: October 2009 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: HYDNAZMARS1 Switch Type: Ribbon/Genband/Nortel RSC Prefixes Served: (520) 356 Notes: Source: Craig L.
Hayden "Dudleyville"	Listing Updated: January 2011 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: DDVLAZNMRS1 Switch Type: Ribbon/Genband/Nortel RSC Prefixes Served: (520) 357 Notes: Source: Craig L.
Hayden "Kearny"	Listing Updated: October 2009 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: KRNYAZMARS1 Switch Type: Ribbon/Genband/Nortel RSC Prefixes Served: (520) 363 Notes: Source: Craig L.
Lone Butte	Listing Updated: August 2010 Operating Company: Gila River Telecom CLLI: LNBTAZXCDS1 Switch Type: Coppercom CSX 1100 Media Gateway Prefixes Served: (520) 215, 315, 418, 430, 550, 562, 796 Notes: This is the HQ of Gila River Telecom and is the central office for a number of ratecenters under a single switch. This telephone company was started in the 1980s to offer better telephone service to the people of the Gila River nation. Source: Craig L.
Lone Butte "Blackwater"	Listing Updated: May 2011 Operating Company: Gila River Telecom CLLI: (was BLWRAZXADS0) Switch Type: (C1100 remote node) Prefixes Served: (520) 215 Notes: Source: Craig L.
Lone Butte "Casa Blanca"	Listing Updated: October 2011 Operating Company: Gila River Telecom CLLI: (was CSBLAZXADS0) Switch Type: (C1100 remote node) Prefixes Served: (520) 315 Notes: Source: Craig L.
Lone Butte "Komatke"	Listing Updated: February 2012 Operating Company: Gila River Telecom CLLI: (was KMTKAZXADS0) Switch Type: (C1100 remote node) Prefixes Served: (520) 550 Notes: Source: Craig L.
Lone Butte "Stotonic"	Listing Updated: February 2012 Operating Company: Gila River Telecom CLLI: (was STTNAZXADS0) Switch Type: (C1100 remote node) Prefixes Served: (520) 418 Notes: Source: Craig L.
Lone Butte "Maricopa Village/Laveen"	Listing Updated: December 2010 Operating Company: Gila River Telecom CLLI: (was MRVGAZXCDS0) Switch Type: (C1100 remote node) Prefixes Served: (520) 430 Notes: Source: Craig L.
Lone Butte "Sacaton"	Listing Updated: August 2010 Operating Company: Gila River Telecom CLLI: (was SCTNAZXCDS0) Switch Type: (C1100 remote node) Prefixes Served: (520) 562 Notes: Source: Craig L.
Nogales "Main"	Listing Updated: November 2010 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: NGLSAZMARS1 Switch Type: Nokia/Alcatel/Lucent 5ESS Remote Prefixes Served: (520) 285, 287, 397 Notes: Source: Craig L.
Nogales "Midway" Photo 2	Listing Updated: April 2021 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: NGLSAZMWDS0 Switch Type: Nokia/Alcatel/Lucent 5ESS Prefixes Served: (520) 281, 375, 377, 761 Notes: Photo 2 is the original by Craig L. in November 2010. Current picture source: GSV.
Nogales "Patagonia Main"	Listing Updated: August 2010 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: PTGNAZMARS1 Switch Type: Ribbon/Genband/Nortel RSC Prefixes Served: (520) 394 Notes: Source: Craig L.
Nogales "Patagonia Elgin"	Listing Updated: October 2011 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: PTGNAZMARS1 Switch Type: Ribbon/Genband/Nortel RSC Prefixes Served: (520) 455 Notes: Source: Craig L.
Nogales "Rio Rico"	Listing Updated: February 2012 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: NGLSAZ03RS2 Switch Type: Nokia/Alcatel/Lucent 5ESS Remote Prefixes Served: None Notes: A remote off of Nogales Midway but does not have any unique prefixes of its own. Source: Craig L.
Nogales "Benedict Mountain"	Listing Updated: February 2012 Operating Company: Verizon Wireless CLLI: NGLSAZAGCM1 Switch Type: Unknown Prefixes Served: None Notes: A mobile telephone switching office (MTSO) on a high remote mountain top. Source: Craig L.
Pearce	Listing Updated: November 2011 Operating Company: Valley Telephone Cooperative CLLI: PERCAZXCDS0 Switch Type: Ribbon/Genband/Nortel DMS-10 Prefixes Served: (520) 558, 642, 824, 826, 845, 847 (575) 557 (928) 359, 687, 828 Notes: Serves a number of ratecenters from a single swtich, also serving a ratecenter in New Mexico. Source: Craig L.
Portal	Listing Updated: February 2012 Operating Company: Valley Telephone Cooperative CLLI: (was PRTLAZXCDS0) Switch Type: Ribbon/Genband/Nortel DMS-10 Prefixes Served: (520) 558 (575) 557 Notes: Also serves Rodeo, NM. Source: Craig L.
San Manuel "Main" Photo 2	Listing Updated: April 2021 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: SNMNAZMADS0 Switch Type: Ribbon/Genband/Nortel DMS-100 Prefixes Served: (520) 385 Notes: Photo 2 is the original by Craig L. in January 2011. Current picture source: GSV.
San Manuel "Mammoth"	Listing Updated: October 2009 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: MMTHAZMARS1 Switch Type: Ribbon/Genband/Nortel RSC Prefixes Served: (520) 487 Notes: Source: Craig L.
San Manuel "Oracle"	Listing Updated: January 2011 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: ORCLAZMARS1 Switch Type: Ribbon/Genband/Nortel RSC Prefixes Served: (520) 896 Notes: Source: Craig L.
San Simon	Listing Updated: February 2012 Operating Company: Valley Telephone Cooperative CLLI: (was SNSMAZXCDS0) Switch Type: Ribbon/Genband/Nortel DMS-10 Prefixes Served: (520) 845 Notes: Source: Craig L.
Santa Rosa	Listing Updated: January 2013 Operating Company: Tohono O'Odham Utility Authority CLLI: SNRSAZXARS0 Switch Type: Digital Switch (unknown type) Prefixes Served: (520) 361 Notes: Source: Craig L.
Sasabe	Listing Updated: June 2014 Operating Company: TDA/Arizona Telephone Company CLLI: SASBAZXCGT0 Switch Type: Trunk Gateway Prefixes Served: (520) 823 Notes: Source: Craig L.
Sells	Listing Updated: April 2011 Operating Company: Tohono O'odham Utility Authority CLLI: SLLSAZXADS1 Switch Type: Nokia/Alcatel/Lucent 5ESS Prefixes Served: (520) 383 Notes: Source: Craig L.
Sierra Vista "Main" Photo 2	Listing Updated: April 2021 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: SRVSAZMADS0 Switch Type: Ribbon/Genband/Nortel DMS-100 Prefixes Served: (520) 417, 439, 452, 458-9, 515, 533, 538 Notes: Photo 2 is the original by Craig L. in August 2010. Current picture source: GSV.
Sierra Vista "North"	Listing Updated: August 2010 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: SRVSAZNORS1 Switch Type: Ribbon/Genband/Nortel RSC Prefixes Served: (520) 456 Notes: Source: Craig L.
Sierra Vista "South" Photo 2	Listing Updated: April 2021 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: SRVSAZSODS0 Switch Type: Ribbon/Genband/Nortel DMS-100 Prefixes Served: (520) 378, 803 Notes: Photo 2 is the original by Craig L. in August 2010. Current picture source: GSV.
Silverbell "Eloy" Photo 2	Listing Updated: January 2012 Operating Company: Midvale Telephone Company CLLI: ELOYAZ05DS0 Switch Type: Redcom Laboratories IGM-MT Prefixes Served: (520) 898 Notes: Source: Craig L.
Sunizona	Listing Updated: November 2011 Operating Company: Valley Telephone Cooperative CLLI: (was SNZNAZXCDS0) Switch Type: Ribbon/Genband/Nortel DMS-10 Prefixes Served: (520) 824 Notes: Source: Craig L.
Superior	Listing Updated: July 2010 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: SPRRAZMARS1 Switch Type: Ribbon/Genband/Nortel RSC Prefixes Served: (520) 689 Notes: Source: Craig L.
Tombstone	Listing Updated: December 2009 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: TMBSAZMARS1 Switch Type: Ribbon/Genband/Nortel RSC Prefixes Served: (520) 457 Notes: Source: Craig L.
Tucson "Main" Photo 2 | Photo 3 | Photo 4 | Photo 5 Photo 6 | Photo 7 | Photo 8	Listing Updated: April 2021 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: TCSNAZMADS1 Switch Type: Nokia/Alcatel/Lucent 5ESS Prefixes Served: (520) 205-6, 209, 388, 594, 617, 620-4, 626, 628-9, 638, 670, 695, 740, 770, 791-2, 798, 838, 872, 879-80, 882, 884, 903 Notes: Photos 2-8 are the original ones by Craig L. in November 2010. Current photo: GSV. Also home to an AT&T Long Lines tandem in the building next door (114-T).
Tucson "Catalina" Photo 2 | Photo 3	Listing Updated: April 2021 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: TCSNAZCADS0 Switch Type: Ribbon/Genband/Nortel DMS-100 Prefixes Served: (520) 232, 299, 529, 577, 615 Notes: Photos 2 and 3 are the originals from May 2011. Photo 3 shows some more detail of the door area and it's period stone work. Source: Craig L.
Tucson "Coronado" Photo 2 | Photo 3	Listing Updated: April 2021 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: CRNDAZMADS1 Switch Type: Ribbon/Genband/Nortel DMS-100 Prefixes Served: (520) 818, 825 Notes: Photo 2 is from June 2011. Photo 3 is from October 2009. Both originals by Craig L. Current photo: GSV.
Tucson "Cortaro" Photo 2	Listing Updated: April 2021 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: TCSNAZCODS0 Switch Type: Nokia/Alcatel/Lucent 5ESS Prefixes Served: (520) 572, 579, 744 Notes: Photo 2 is the original by Craig L. in November 2010. Current picture source: GSV.
Tucson "Craycroft" Photo 2 | Photo 3	Listing Updated: April 2021 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: TCSNAZCRDS0 Switch Type: Nokia/Alcatel/Lucent 5ESS Prefixes Served: (520) 512-4, 519, 570-1, 584, 745, 747-8, 750, 790 Notes: Photos 2 and 3 are the original by Craig L. in May 2011. Photo 3 shows some more detail of the decorative entry and tilework. Source: Craig L.
Tucson "East" Photo 2	Listing Updated: April 2021 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: TCSNAZEADS0 Switch Type: Nokia/Alcatel/Lucent 5ESS Prefixes Served: (520) 318-27, 784, 795, 874, 881 Notes: Photo 2 is the original by Craig L. in August 2010. Current picture source: GSV.
Tucson "Flowing Wells" Photo 2	Listing Updated: April 2021 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: TCSNAZFWDS0 Switch Type: Ribbon/Genband/Nortel DMS-100 Prefixes Served: (520) 292-3, 407-8, 690, 696,887-8 Notes: Photo 2 is the original by Craig L. in May 2011. Current picture source: GSV.
Tucson "Green Valley" Photo 2	Listing Updated: April 2021 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: GNVYAZMADS0 Switch Type: Ribbon/Genband/Nortel DMS-100 Prefixes Served: (520) 393, 399, 625, 648 Notes: Photo 2 is the original by Craig L. in August 2010. Current picture source: GSV.Source: Craig L.
Tucson "Marana Main"	Listing Updated: May 2010 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: MARNAZMARS1 Switch Type: Ribbon/Genband/Nortel RSC Prefixes Served: (520) 616 Notes: Source: Craig L.
Tucson "Marana South"	Listing Updated: October 2011 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: MARNAZ03RS1 Switch Type: Ribbon/Genband/Nortel RSC Prefixes Served: (520) 682 Notes: Source: Craig L.
Tucson "Marana West"	Listing Updated: May 2011 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: MARNAZ02RS1 Switch Type: Ribbon/Genband/Nortel RSC Prefixes Served: (520) 665 Notes: Source: Craig L.
Tucson "Mount Lemon"	Listing Updated: October 2011 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: TCSNAZMLRS2 Switch Type: Nokia/Alcatel/Lucent 5ESS Prefixes Served: (520) 576 Notes: Source: Craig L.
Tucson "North" Photo 2	Listing Updated: April 2021 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: TCSNAZNODS0 Switch Type: Nokia/Alcatel/Lucent 5ESS Prefixes Served: (520) 218-9, 225, 229, 291, 297, 410, 469, 489, 498, 516, 531, 544, 566, 575, 712, 742, 793, 797, 877-8 Notes: Photo 2 is the original by Craig L. in May 2011. Current picture source: GSV.
Tucson "Rincon" Photo 2	Listing Updated: April 2021 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: TCSNAZRNDS0 Switch Type: Ribbon/Genband/Nortel DMS-100 Prefixes Served: (520) 258, 290, 296, 298, 546, 721-2, 731, 733, 751, 873, 885-6 Notes: Photo 2 is the original by Craig L. in May 2011. Current picture source: GSV.
Tucson "South" Photo 2 | Photo 3 Photo 4	Listing Updated: April 2021 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: TCSNAZSODS0 Switch Type: Nokia/Alcatel/Lucent 5ESS Prefixes Served: (520) 243, 294-5, 434, 573, 741, 746, 794, 799, 806-7, 889 Notes: Photos 2-4 are the original from May 2011. Photo 3 shows a straight shot of the entry, photo 4 is of the mailbox out front, still marked as Mountain Bell. Current photo source: GSV
Tucson "Southeast"	Listing Updated: August 2010 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: TCSNAZSEDS0 Switch Type: Ribbon/Genband//Nortel DMS-100 Prefixes Served: (520) 574, 662-4 Notes: Source: Craig L.
Tucson "Southwest" Photo 2	Listing Updated: April 2021 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: TCSNAZSWDS0 Switch Type: Ribbon/Genband/Nortel DMS-100 Prefixes Served: (520) 578, 822, 883, 908 Notes: Photo 2 is the original by Craig L. in May 2011. Current picture source: GSV.
Tucson "Tanque Verde"	Listing Updated: May 2011 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: TCSNAZTVDS0 Switch Type: Nokia/Alcatel/Lucent 5ESS Prefixes Served: (520) 749, 760 Notes: Source: Craig L.
Tucson "Tubac"	Listing Updated: August 2010 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: TUBCAZMARS1 Switch Type: Nokia/Alcatel/Lucent 5ESS Remote Prefixes Served: (520) 398 Notes: Source: Craig L.
Tuscon "Vail North"	Listing Updated: December 2009 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: VAILAZNORS1 Switch Type: Ribbon/Genband/Nortel RSC Prefixes Served: (520) 647 Notes: Source: Craig L.
Tuscon "Vail South"	Listing Updated: Septembe 2011 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: VAILAZSODS0 Switch Type: Ribbon/Genband/Nortel RSC Prefixes Served: (520) Notes: Source: Craig L.
Tucson "West"	Listing Updated: May 2011 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: TCSNAZWERS1 Switch Type: Ribbon/Genband/Nortel RSC Prefixes Served: (520) 743 Notes: Source: Craig L.
West San Simon "Santa Rosa"	Listing Updated: April 2011 Operating Company: Tohono O'odham Utility Authority CLLI: SNRSAZXCRS0 Switch Type: DS (unknown type) Prefixes Served: (520) 362 Notes: Source: Craig L.
Whitlow	Listing Updated: July 2010 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: WHTLAZMADS0 Switch Type: Ribbon/Genband/Nortel DMS-10 Prefixes Served: (520) 463 Notes: Source: Craig L.
Willcox Photo 2	Listing Updated: November 2011 Operating Company: CenturyLink/Qwest/US West/Mountain Bell CLLI: WLCXAZMARS1 Switch Type: Ribbon/Genband/Nortel RSC Prefixes Served: (520) 384 Notes: I wouldn't put a payment in the payment box in Photo 2. Source: Craig L.