021.4819.3617.83017.465.307179018021.4919.3717.84017.4710019012019.0121.5019.3817.85017.481601419.020021.5119.3917.86017.4919.030019.04021.5219.4017.87017.50019.0539610630019.0621.5319.4117.880369382717.51019.0719.1121.5419.4217.89317.5219.08170039944419.0923975928021.5519.4317.9017.53519.11619.1321.5619.4417.9117.54719.1415723000021.5719.4517.92819.1517.552094618.8617.311318.334718.8717.33481418.345018.8817.351518.350018.8917.361618.3600018.9017.371718.37000018.9117.3817.0118.38000018.9217.3917.0218.3918.9317.4017.0318.401218.9417.4117.0418.41318.9517.4217.0518.423221.9817.8618.3622.13322.217.8721.9918.373522.33622.0017.8818.383717.893822.0118.393917.9022.0218.40404122.0317.9118.41424322.0417.9218.424422.0517.9318.43454622.0617.9418.44474922.0717.9518.45Non-power Goods or Services Provided for Affiliate214320.93020.434420.9420.4445046020.95120.4524803234920.97020.4645020.99520.4706021.0020.4870039.1821.0120.49100021.021120.50012021.0320.5113015021.0420.52160172518.93319.9320.462641818.9419.9420.47275192818.9519.9520.4820293018.9619.962120.49312218.9719.9720.5032233318.9819.9820.51352418.9919.9920.522519.0020.002620.5314108211012295478319.0120.0120.5419.0220.0220.5514.219.431714.32119.44234768717182519.452819.46314977259976511906203519.476243064319.4848768919.493782712174910704656122719.503819.5133129164180119.5232219.9617.931.418.96203480217.4319.4693296818.4317.561.5104519.9717.9418.9717.44219.471018.4417.5762.119.9817.9518.9817.4519.48718.4517.582.2819.9917.962.318.9917.4619.4918.4617.5992.417.9720.0019.0017.4719.502.51118.4717.605395192256219542122.620.0119.0117.4819.5117.981318.4817.612.71420.0219.0217.4919.5217.9918.4917.6219.0317.5019.5318.0020.0318.5017.6318.0120.04219.0417.5119.54318.5117.64418.0220.0519.0517.5219.5518.5217.65522.0817.0686103900132811.118711.222.0917.0711.3646511.422.1017.0811.56722.1117.096911.611.722.1217.1011.811.922.1617.111217.127612.1771412.1117.1312.12112.1317.1412212.217.151312.32594792421.055017.9666521.0617.977080621.07017.980023.10721.08017.99023.29.10023.39.11821.09018.0009.1200921.1018.0109.13009.1401021.11018.0209.15009.21121.12018.0309.3001221.13018.049.4009.525643136101321.14018.0509.60R1221.5820.5318.466.16106.171421.5920.5418.476.18156.1921.6020.5518.48256.221.6120.5618.496.316.421.6220.5718.5036.56.621.6320.5818.5156.721.6420.5918.526.876.921.6520.6018.539783997.121.6620.6118.54117.11113642121.6720.6218.557.121319.5320.0319.5420.041219.5520.05131419.5620.06151619.5720.071719.5820.08181919.5920.09202119.6020.102220.1119.61232420.1219.622520.56121320.57141520.58161720.591820.60192120.61222320.622420.63252620.641928052327272820.65291959689119.0320.0618.5317.664019.0420.0718.5417.6719.0520.0818.5517.6819.0620.0918.5617.6919.0720.1018.5717.7019.0820.1118.5817.71219.0920.1218.5917.723419.1020.1318.6017.735619.1120.1418.6117.74719.1220.1518.6217.751417.5319.5618.031517.5419.5718.041617.5519.5818.051717.5619.5918.0617.0117.5719.6018.0717.0217.5819.6118.0817.0317.5919.6218.0917.0417.6019.6318.1017.0517.6119.6418.1117.0617.6219.6518.121717.1621.1519.0621.68915.118.56181015.217.1721.1819.0721.691918.57211315.32017.1821.1919.081221.70415.418.582113515.52217.1921.2019.0921.711418.596231517.2021.2119.1021.7218.6024162517.2121.2319.111721.7318.6126182717.2221.2419.1221.741918.622817.2321.2519.1321.7518.632917.2421.2619.1421.7618.6417.2521.2719.1521.7718.6518.0618.07313518.08974289933945638718.0910953720439742899331786882714108211018.1012295478318.1118.1218.1318.141979261615118159218.1520.137425703020.661411805291520.1420.6780411620.151820577720.6820.1620.6920.17114482020.7020.1820.7120.19120.722320.2020.73420.21520.74620.2220.75712.419.1320.1620.631512.57820.1719.1412.620.6417912.719.1520.181020.652312.812.920.1919.1620.6619.1720.2020.6719.1820.2120.6819.1920.2220.69582967919.2020.2327388471320.706562false19.2120.2420.712121.119.2220.2521.220.721222219.6319.6617.7612322626.119.6419.6717.7724326.11American Electric Power25Service Corporation19.6519.682417.7826.1226726.1392719.6619.6917.7926.141028Southwest Power26.1519.6719.7017.80291326.163119.6819.7117.8126.23225.126.33319.6919.72617.8226.473526.519.7019.73817.8336026.625.293719.7119.7417.8426.710026.8819.7219.7517.85826.97.139.717.6317.2618.637.149.817.277.1517.6418.649.97.1617.6517.2818.657.177.1817.6617.2918.667.197.217.6717.3018.677.2117.6817.3118.687.37.417.6917.3218.697.57.617.7017.3318.707.717.7117.3418.717.87.917.7217.3518.72675100018.1317.0719.1621.7814108211018.1417.0819.1721.7917.0919.1821.8018.1517.1019.1921.8118.16842098420917.1119.2021.8218.1717.1219.2121.8318.1817.1319.2221.841.118.19217.1419.2321.8518.2017.1519.2421.8618.2115681655717.1619.2521.8718.221458031770151618192021222324156816557252627282930113111.12618.1621.2820.7318.66302273118.1721.292820.7418.674322918.1821.303320.7518.68530343121.3118.1920.7618.6935732143621.3218.203320.7718.708373421.33113818.21120.7818.713351439853621.3418.2220.7918.721740737194118.2321.3593820.8018.73214211139218.242321.364320.8118.7413404434118.2521.3720.8218.75345444220.23619.2320.76719.2420.2420.778919.2520.2520.781019.2620.261120.791219.2720.2720.80131419.2820.2820.8115419.2920.291620.821726970163319.3020.3020.83181919.3120.3120.8411117896655.119.3220.3220.85255.2233721784019.7320.260019.7420.270019.7520.28051619.765020.2971119.7720.301601520019.78020.310180019.79020.32210002419.8020.3302819.81020.343419.8220.3504119.2619.7618.2317.3618.731530209217.3719.271470436919.7718.2418.7470331463765710534819.2819.7818.2517.381818.751919.2919.7918.2617.3918.7619.3019.8018.2717.4018.7719.3119.8118.2817.4118.7819.3219.8218.2917.4218.7919.3319.8318.3017.4318.80385319.3419.8418.3117.4418.815419.3519.8518.3217.455518.82817.7321.8818.762690012017.7421.891018.77200211017.7521.9018.7812322231317.7621.9118.794240142506017.7721.9215018.801591530260164023893017.7821.9318.8156154231714711380493622218188268017.7921.9418.826399956428751916.117.8021.952026.1102118.832232186.1207017.8121.9618.84022116.13179759591319002317975959136.141317.8221.972318.8515856421024135430906.1515Wdesk from Workiva17.1721.3833.10false03.1117.1821.394Jeffrey W. Hoersdig, Assistant Controller1212 East 6th StreetTulsa, Oklahoma 741193.12OKThe generation, transmission and sale of electric energy.All operations within the State of Oklahoma.2617.1921.40false53.223.3317.2021.4163.443.5517.2121.4273.66131.117.2321.4383.727777831.23.8387917.2421.44C00053693.9698071017.2621.4510818118217.2721.46119128310148417.2821.47121114.18520.3318.2620.8320.3418.2720.8420.3518.2820.8520.3618.2920.8620.3718.3020.8720.3818.3120.8820.3918.3220.8920.4018.3320.9020.4118.3420.9120.4218.3520.9262719.83527.119.84627.1127.12719.8527.13827.1419.86927.1519.8727.161027.219.881127.31227.419.8927.51319.9027.61427.719.911527.827.919.921619.8620.364220.864319.8720.3720.874419.8820.3820.884519.8920.3920.8919.9020.4020.9082063119.9120.4120.9119.9220.4220.9219.9320.4320.9319.9420.44120.941.11.219.9520.4520.95121.319.3318.836567061692109187045011513469661157719.3418.841619.351818.852019.3618.861870450115187045011513.119.3718.8713.219.3818.8813.319.39302909418.89319.4018.904519.4118.91619.4218.9278 C000536 ALTUS JUNCTION - OK, Transmission, , 138, 69, 13.8, 93.3,  2021-01-012021-12-31 C000536 BARTLESVILLE COMANCHE - OK, Distribution, , 138, 70.5, 36.2, 30,  2021-01-012021-12-31 C000536 DAWSON - OK, Transmission, , 138, 13.8, , 33.3,  2021-01-012021-12-31 C000536 McAlester Army Ammunitions Plant (6,7), OS, 2021-01-012021-12-31 C000536 ferc:ExciseTaxMember 2020-12-31 C000536 GRADY COUNTY POD - OK, Transmission, , 138, 4.36, , 75,  2021-12-31 C000536 ALTUS JUNCTION - OK, Transmission, , 34.5, 13.8, , 5,  2021-01-012021-12-31 C000536 A. (2) Transmission, 2 Items < $50,000 2021-01-012021-12-31 C000536 WEATHERFORD SE - OK, Transmission, , 138, 66, 13.8, 50,  2021-12-31 C000536 TL66-119 HUGO, VALLIANT 345 KV, 2, 5.37, 2, 477.0  ACSR and 795 ACSR, 0, 0 2021-01-012021-12-31 C000536 ferc:ElectricUtilityMember Excise Tax, Excise Tax, , 21 2021-01-012021-12-31 C000536 342 - Riverside U3&4 2021-01-012021-12-31 C000536 BIRD CREEK PUMP - OK, Distribution, , 138, 4.16, , 5.6,  2021-12-31 C000536 Windrenew Project - Approved on PSO's Cause No. PUD 201800138 Order No 688455 2021-01-012021-12-31 C000536 MOUND ROAD - OK, Distribution, , 13.8, 0, 0, 0, STATCAP 2021-01-012021-12-31 C000536 PSO-D Spare Equipment CIferc:ElectricUtilityMember 2021-12-31 C000536 Other (provide details in footnote): 2021-01-012021-12-31 C000536 395 2021-01-012021-12-31 C000536 398 2021-01-012021-12-31 C000536 344 - Riverside U3&4 2021-01-012021-12-31 C000536 Non-Roadway Lght 151-163 2021-01-012021-12-31 C000536 RIVERSIDE 1 & 2 2021-12-31 C000536 TL81-843 TULSA NORTH SUB, BARTLESVILLE SUB, 1, 5.37, 1, 795 ACSR, , 2021-01-012021-12-31 C000536 TOTAL GENERAL PLANT 2021-01-012021-12-31 C000536 SOUTHWESTERN STATION - OK, Transmission, , 69, 13.8, , 5.25,  2021-12-31 C000536 TL66-109 CATOOSA, DAWSON, 2, 1.26, 0, 477.0 ACSR, , 2021-01-012021-12-31 C000536 GS PSF 304 2021-01-012021-12-31 C000536 Research and Other Services, AEPSC 2021-01-012021-12-31 C000536 Other 2021-01-012021-12-31 C000536 GS-Net Meter TOD 257 2021-01-012021-12-31 C000536 TULSA 2021-12-31 C000536 LPL 250 2021-01-012021-12-31 C000536 312 - Northeast U3 2021-01-012021-12-31 C000536 CARSON - OK, Distribution, , 138, 14.15, , 89.6,  2021-01-012021-12-31 C000536 TL81-816 NORTHEASTER POWER STATION, BARTLESVILLE SOUTHEAST, 1, 23.38, 1, 1272.0  ACSR, , 2021-01-012021-12-31 C000536 402 - Maintenance Exp 2021-01-012021-12-31 C000536 TL81-819 SOUTHWESTERN PLANT, HOBART JCT SUB, 2, 27.78, 1, 397 ACSR, , 2021-01-012021-12-31 C000536 Atoka D-Station Workferc:ElectricUtilityMember 2021-01-012021-12-31 C000536 TL81-565 COMANCHE, 112TH & W. GORE, 1, 19.69, 1, (T2) 636  ACSR, , 2021-01-012021-12-31 C000536 Expenses Minor in Nature < $25,000 2021-01-012021-12-31 C000536 PSO-T Spare Equipment CIferc:ElectricUtilityMember 2021-12-31 C000536 Customer and Other Advance Receipts 2021-12-31 C000536 WEST EDISON - OK, Distribution, , 138, 13.8, , 74.6,  2021-01-012021-12-31 C000536 Pryor Junction distributionferc:ElectricUtilityMember 2021-01-012021-12-31 C000536 ferc:NextTwelveMonthsMemberferc:SulfurDioxideMember 2021-12-31 C000536 Sales & Use Tax, Sales And Use Tax, OK, 21 2021-12-31 C000536 TL81-807 ONETA, TULSA SOUTHEAST, 3, 5.64, 2, 795 ACSR AND T2 397.5 ACSR, 0, 0 2021-01-012021-12-31 C000536 Other License and Fees Tax, Other License And Fees Tax, WY, 19 2021-12-31 C000536 VALLIANT 345 - OK, Transmission, , 69, 0, 0, 0, STATCAP 2021-12-31 C000536 DAWSON - OK, Transmission, , 138, 69, 13.8, 84,  2021-01-012021-12-31 C000536 ATOKA 138 - OK, Transmission, , 138, 23.9, , 22.4,  2021-12-31 C000536 0, 0 2021-01-012021-12-31 C000536 RIVERSIDE 345KV - OK, Transmission, , 345, 138, 34.5, 1350,  2021-12-31 C000536 ANTLERS - OK, Distribution, , 69, 13.8, , 14,  2021-12-31 C000536 PERNELL - OK, Distribution, , 138, 4.36, 2.52, 15,  2021-12-31 C000536 MINGO - OK, Distribution, , 13.8, 0, 0, 0, STATCAP 2021-01-012021-12-31 C000536 SKIATOOK WATER PUMP - OK, Distribution, , 138, 2.5, , 7,  2021-12-31 C000536 American Electric Power 2021-01-012021-12-31 C000536 COMANCHE GAS 2021-01-012021-12-31 C000536 ferc:ElectricPlantInServiceMemberferc:ElectricUtilityMember 2020-12-31 C000536 AFTON CONTL PIPE(CHEROKE - OK, Distribution, , 69, 2.4, , 3.75,  2021-12-31 C000536 Real Estate & Workplace Svcs, AEPSC 2021-01-012021-12-31 C000536 Other (provide details in footnote): 2021-01-012021-12-31 C000536 HAMMON JUNCTION - OK, Distribution, , 69, 34.5, , 25,  2021-01-012021-12-31 C000536 77TH & MEMORIAL - OK, Distribution, , 13.8, 0, 0, 0, STATCAP 2021-01-012021-12-31 C000536 RS 038 2021-01-012021-12-31 C000536 Traffic Signal 203 2021-01-012021-12-31 C000536 TL81-522 RIVERSIDE PLANT, TULSA PLANT W/TAP, 2, 5.39, 1, 556.5 ACSR , 0, 0 2021-01-012021-12-31 C000536 WAPANUCKA - OK, Distribution, , 138, 4.36, , 40,  2021-01-012021-12-31 C000536 81ST & GARNETT - OK, Distribution, , 138, 0, 0, 0, STATCAP 2021-12-31 C000536 Steam Power Generation - Maintenance, AEPSC 2021-01-012021-12-31 C000536 PSO Distr Pre Eng Parentferc:ElectricUtilityMember 2021-01-012021-12-31 C000536 TL81-562 MOHAWK, AMERICAN AIRLINES, 1, 4.49, 1, 1272.0  ACSR, 0, 0 2021-01-012021-12-31 C000536 RED OAK PUMP - OK, Distribution, , 4.16, 0, 0, 0, STATCAP 2021-01-012021-12-31 C000536 Other Debit or Cr. Items (Describe, details in footnote):ferc:ElectricPlantInServiceMemberferc:ElectricUtilityMember 2021-01-012021-12-31 C000536 GROVE - OK, Transmission, , 138, 13.8, , 44.8,  2021-01-012021-12-31 C000536 PRUE - OK, Distribution, , 34.5, 13.2, , 1.68,  2021-01-012021-12-31 C000536 TL90-909 NORTHEASTERN POWER STATION, TULSA NORTH, 3, 1.4, 1, 2267 ACAR, , 2021-01-012021-12-31 C000536 TL81-523 RIVERSIDE PLANT, OG&E INTERCONNECT, 2, 1.9, 3, 1020  ACSR, 795 ACSR AND 1272 KCM, 0, 0 2021-01-012021-12-31 C000536 Senior Unsecured - Series F - 4.11%                                                2021-12-31 C000536 0ferc:JuneMember 2021-01-012021-12-31 C000536 MAYO ROAD - OK, Distribution, , 13.8, 0, 0, 0, STATCAP 2021-12-31 C000536 OWASSO 109TH STREET - OK, Distribution, , 138, 13.8, , 45,  2021-12-31 C000536 Federal Taxes, Federal Tax, , 2020-12-31 C000536 CARNES - OK, Distribution, , 34.5, 13.8, , 5.25,  2021-12-31 C000536 Legal GC/Administration, AEPSC 2021-01-012021-12-31 C000536 WAURIKA - OK, Distribution, , 69, 4.36, , 7,  2021-12-31 C000536 TL81-559 BARTLESVILLE SOUTHEAST SUB, BARTLESVILLE COMANCHE SUB, 1, 3.28, 1, 636.0  ACSR, 0, 0 2021-01-012021-12-31 C000536 ferc:ElectricUtilityMember Purchase Tulsa Hubsite 2021-01-012021-12-31 C000536 TL66-613 CORNVILLE, CYRIL, 1, 0.4, 1, 477.0  ACSR, 0, 0 2021-01-012021-12-31 C000536 ferc:FederalTaxMember 2020-12-31 C000536 TL66-619 LAWTON EASTSIDE, LAWTON WOLF CREEK, 1, 5.18, 0, 477.0 ACSR, 0, 0 2021-01-012021-12-31 C000536 ADAIR - OK, Distribution, , 69, 13.8, , 10.5,  2021-12-31 C000536 AGRICO-TERRA NITROGEN - OK, Distribution, , 138, 4.36, , 28,  2021-12-31 C000536 96TH & YALE - OK, Distribution, , 138, 13.8, , 37.3,  2021-01-012021-12-31 C000536 ALTUS JUNCTION - OK, Transmission, , 34.5, 13.8, , 5,  2021-12-31 C000536 LEHIGH CITY - OK, Distribution, , 138, 23.9, , 30.5,  2021-01-012021-12-31 C000536 SAND SPRINGS 138KV - OK, Transmission, , 138, 13.8, , 74.6,  2021-01-012021-12-31 C000536 SFAS 109 Deferred Federal Income Tax 2020-12-31 C000536 DARBY - OK, Distribution, , 34.5, 13.2, , 3.12,  2021-01-012021-12-31 C000536 Other 2021-01-012021-12-31 C000536 02200609-5107, 43991, ER18-195-000 2021-01-012021-12-31 C000536 LED Light 170-177 2021-01-012021-12-31 C000536 CLAYTON - OK, Distribution, , 138, 13.8, , 5.6,  2021-12-31 C000536 VILLA GROVE - OK, Distribution, , 13.2, 4.36, , 4.68,  2021-01-012021-12-31 C000536 TL81-612 MCALESTER CITY BUS TIE, , 1, 0.04, 0, 795 ACSR, 0, 0 2021-01-012021-12-31 C000536 TL81-821 CORNVILLE SUB, DUNCAN SUB W/TAP, 2, 0.86, 1, 477 ACSR, , 2021-01-012021-12-31 C000536 TL81-838D LYNN LANE TAP, , 1, 1.01, 1, 795 ACSR, 0, 0 2021-01-012021-12-31 C000536 Ed-Ci-Psoco-D Ast Imp 2021-01-012021-12-31 C000536 TL81-836 RED OAK, EUFAULA (SWPA), 1, 16.53, 0, 4/0 ACSR, 0, 0 2021-01-012021-12-31 C000536 184 - Clearing Accounts 2021-01-012021-12-31 C000536 Ed-Ci-Psoco-D Ast Impferc:ElectricUtilityMember 2021-01-012021-12-31 C000536 TL81-810 TULSA SOUTHEAST SUB, CATOOSA SUB, 3, , 2, 1026 ACCC, , 2021-01-012021-12-31 C000536 0ferc:ElectricUtilityMember 2021-01-012021-12-31 C000536 EARLSBORO - OK, Distribution, , 138, 4.36, , 40,  2021-12-31 C000536 TL81-847 CRAIG JCT SUB, (SWEPCO) INTERCONNECT ARKANSAS, 1, 9.3, 1, 1272 ACSR, 0, 0 2021-01-012021-12-31 C000536 316.3 - Riverside 2021-01-012021-12-31 C000536 TL81-849 OKMULGEE, HENRYETTA, 1, 13.64, 0, 1272.0  ACSR, 0, 0 2021-01-012021-12-31 C000536 GLENHAVEN - OK, Distribution, , 13.2, 4.36, , 9.36,  2021-12-31 C000536 TL81-827 BARTLESVILLE SOUTHEAST SUB, SHIDLER SUB W/TAP COMMERCE, 1, 0.14, 1, 795 ACSR, 0, 0 2021-01-012021-12-31 C000536 WS-CI-PSOCo-G PPBferc:ElectricUtilityMember 2021-12-31 C000536 TL81-521  RIVERSIDE PLANT, TULSA PLANT, 2, 3.37, 1, 795 ACSR, , 2021-01-012021-12-31 C000536 Oklahoma Gas and Electric Company(10), EX, 2021-01-012021-12-31 C000536 MCALESTER CHEROKEE - OK, Distribution, , 23, 4.36, , 9.37,  2021-12-31 C000536 WHIRLPOOL (PO) - OK, Distribution, , 138, 13.8, , 14,  2021-01-012021-12-31 C000536 ferc:ElectricUtilityMember Ft Sill to LES PSO CI 2021-01-012021-12-31 C000536 HOBART CITY - OK, Transmission, , 69, 34.5, 14.4, 27.56,  2021-01-012021-12-31 C000536 ferc:FranchiseTaxMember 2021-12-31 C000536 346 - Weleetka 2021-01-012021-12-31 C000536 LUGS 264 2021-01-012021-12-31 C000536 BARTLESVILLE SOUTHEAST - OK, Transmission, , 138, 13.8, , 74.6,  2021-01-012021-12-31 C000536 OWASSO 88TH & MINGO - OK, Distribution, , 138, 13.8, , 40,  2021-12-31 C000536 DAVIDSON (PO) - OK, Distribution, , 69, 13.09, 4.16, 6.25,  2021-12-31 C000536 PITTSBURG (PO) - OK, Distribution, , 69, 13.2, , 4.5,  2021-12-31 C000536 BARTLESVILLE COMANCHE - OK, Distribution, , 138, 13.8, , 37.3,  2021-12-31 C000536 Other Accounts (Specify, provide details in footnote): 2021-01-012021-12-31 C000536 TL90-909 NORTHEASTERN POWER STATION, TULSA NORTH, 2, 1.95, 2, 2267.0  ACAR and 795 ACSR, 0, 0 2021-01-012021-12-31 C000536 361 2021-01-012021-12-31 C000536 ferc:NitrogenOxideMember Other 2021-01-012021-12-31 C000536 HOBART CITY - OK, Transmission, , 13.8, 0, 0, 0, STATCAP 2021-12-31 C000536 Corporate Human Resources, AEPSC 2021-01-012021-12-31 C000536 Other State Tax, Other State Tax, OH, 20ferc:ElectricUtilityMember 2021-01-012021-12-31 C000536 State Tax, Income Tax, OK, 19 2020-12-31 C000536 ferc:PropertyTaxMember 2020-12-31 C000536 ferc:ElectricUtilityMember PSO-T BlnktProj Under $3M 2021-01-012021-12-31 C000536 394 2021-01-012021-12-31 C000536 HOLLIS - OK, Distribution, , 138, 34.5, , 14,  2021-12-31 C000536 TL81-526 CATOOSA, MAID SUB w/TAP, 1, 3.75, 1, 1272 ACSR, , 2021-01-012021-12-31 C000536 15TH & FULTON - OK, Distribution, , 138, 13.8, , 77.3,  2021-12-31 C000536 SFAS 109 Deferred FIT 2020-12-31 C000536 A. (6)(f) Metering, Advanced Metering Equipment (AMI) Test Bed Development 2021-01-012021-12-31 C000536 ferc:TwoYearsMemberferc:NitrogenOxideMember 2021-12-31 C000536 Customer and Other Advance Receipts 2020-12-31 C000536 ELK CITY - OK, Transmission, , 69, 34.5, 14.4, 27.56,  2021-12-31 C000536 PSO Integrated Resource Plans 2021-01-012021-12-31 C000536 Total Dividends Decl - Common Stk (438)      2021-01-012021-12-31 C000536 MAYO ROAD - OK, Distribution, , 138, 13.8, , 74.6,  2021-12-31 C000536 WARREN MEDICAL CENTER - OK, Distribution, , 138, 13.8, , 74.6,  2021-01-012021-12-31 C000536 LPL 244 2021-01-012021-12-31 C000536 Congestion 2021-01-012021-12-31 C000536 ferc:ElectricUtilityMember 3% 2021-01-012021-12-31 C000536 DUKE - OK, Transmission, , 69, 34.5, , 14,  2021-12-31 C000536 TULSA POWER - OK, Transmission, , 138, 0, 0, 0, STATCAP 2021-01-012021-12-31 C000536 314.3 - Tulsa 2021-01-012021-12-31 C000536 LUGS 264 2021-01-012021-12-31 C000536 DSIT Normalized 2021-01-012021-12-31 C000536 Traverse Wind Project PSO 2021-01-012021-12-31 C000536 Southwest Power Pool (7), OS, 2021-01-012021-12-31 C000536 BARTLESVILLE SOUTHEAST - OK, Transmission, , 13.8, 0, 0, 0, STATCAP 2021-12-31 C000536 FORD GLASS - OK, Distribution, , 138, 13.8, , 74.6,  2021-01-012021-12-31 C000536 ONETA - OK, Transmission, , 345, 141.45, 13.8, 560,  2021-12-31 C000536 Property Tax, Property Tax, WV, 20 2021-01-012021-12-31 C000536 Under-recovery and related amortizations of Deferred Major/Minor Storm Restoration Expenses - Recovery approved per: OCC Cause No. 201300217, Order No. 639314 - 48 months beginning May 2015 OCC Cause No. 201700151, Order No. 672864 48 months beginning March 2018. 2021-01-012021-12-31 C000536 TL81-545 NORTHEASTERN POWER STATION, VINITA JUNCTION 138kV LINE, 1, 0.09, 1, 1272 ACSR, 0, 0 2021-01-012021-12-31 C000536 LOCUST GROVE - OK, Distribution, , 115, 13.09, , 25,  2021-01-012021-12-31 C000536 TL81-606 TALAWANDA, MCALESTER INDUSTRIAL, 1, 8.8, 1, 1533 ACSR, , 2021-01-012021-12-31 C000536 JAMESTOWN - OK, Distribution, , 13.2, 4.36, , 14.04,  2021-12-31 C000536 2020-01-012020-12-31 C000536 TL66-103 WELEETKA PLANT, OG&E INTERCONNECT (SEMINOL), 3, 0.11, 0, 266.8 ACSR, 0, 0 2021-01-012021-12-31 C000536 Agency Fees - Factored Accounts Receivable 2020-12-31 C000536 CATOOSA - OK, Transmission, , 138, 69, 13.8, 54,  2021-12-31 C000536 PSO-D Telecom 2021-01-012021-12-31 C000536 CHEYENNE - OK, Distribution, , 34.5, 4.36, , 5.25,  2021-01-012021-12-31 C000536 State Tax, Income Tax, TX, 18 2021-12-31 C000536 ELGIN JUNCTION - OK, Transmission, , 138, 69, 13.8, 50.4,  2021-12-31 C000536 CORNVILLE - OK, Transmission, , 138, 13.8, , 37.3,  2021-12-31 C000536 MAPLEWOOD - OK, Distribution, , 13.2, 4.36, , 4.68,  2021-12-31 C000536 CLAYTON - OK, Distribution, , 138, 13.8, , 5.6,  2021-01-012021-12-31 C000536 ZUNIS - OK, Distribution, , 138, 13.8, , 74.6,  2021-12-31 C000536 WAGONER - OK, Distribution, , 69, 13.8, , 2.5,  2021-12-31 C000536 TL81-539 MCALESTER SOUTH SUB, LONE OAK SUB , 1, 0.16, 1, 795 ACSR, , 2021-01-012021-12-31 C000536 gridSMART Loan Agreement Promissory Note, 3.00%                                    State Energy Program American Recovery and Reinvestment Act of 2009Revolving Loan Program  Promissory Note - Fixed Rate 14207 SSEP 09 2021-01-012021-12-31 C000536 TL81-501A (RADIAL) SOUTHEAST SUB, KENOSHA SUB, , , , , , 2021-01-012021-12-31 C000536 TL81-810 TULSA SOUTHEAST SUB, CATOOSA SUB, 3, , 2, T2 397.5 ACSR, 0, 0 2021-01-012021-12-31 C000536 0ferc:SeptemberMember 2021-01-012021-12-31 C000536 LPL 248 2021-01-012021-12-31 C000536 TL81-545 NORTHEASTERN POWER STATION, VINITA JUNCTION 138kV LINE, 1, 1.08, 2, 1272 ACSR AND  397.5 ACSR, 0, 0 2021-01-012021-12-31 C000536 IDABEL - OK, Distribution, , 138, 13.8, , 44.8,  2021-01-012021-12-31 C000536 SOUTH HUDSON - OK, Distribution, , 13.8, 0, 0, 0, STATCAP 2021-01-012021-12-31 C000536 Other State Tax, Other State Tax, OH, 20 2020-12-31 C000536 VALLIANT WEYCO #2 - OK, Distribution, , 138, 13.8, , 106,  2021-01-012021-12-31 C000536 RED OAK PUMP - OK, Distribution, , 138, 4.16, , 20,  2021-01-012021-12-31 C000536 ferc:OtherUtilityMember 2021-12-31 C000536 TL81-808 TULSA PLANT SUB, SAND SPRINGS SUB, 3, 4.15, 2,  556.5 ACSR, , 2021-01-012021-12-31 C000536 TL81-810D (RADIAL) LYNN LANE TAP, , 1, 1, 1, 477 ACSR, 0, 0 2021-01-012021-12-31 C000536 TL81-506B CLINTON NATURAL GAS TAP, TLN114:0506B, 1, 0.59, 1, T2 636 ACSR, , 2021-01-012021-12-31 C000536 TULSA POWER - OK, Transmission, , 138, 69, 13.8, 140,  2021-01-012021-12-31 C000536 DSIT ENTRY - NORMALIZED 2021-01-012021-12-31 C000536 10%ferc:ElectricUtilityMember 2021-01-012021-12-31 C000536 TL81-558 MOUND ROAD SUB, SHIDLER/PAWHUSKA, 1, 0.87, 2, 795.0  ACSR, 0, 0 2021-01-012021-12-31 C000536 PRYOR JUNCTION - OK, Transmission, , 115, 69, 13.8, 75,  2021-12-31 C000536 TL81-600 CARSON TAP NORTH, , 1, 0.1, 1, 1233.6 ACSR/TW, 0, 0 2021-01-012021-12-31 C000536 Senior Unsecured Notes, Series C - 3.05%                                          2021-12-31 C000536 ferc:Quarter4Member 0 2021-01-012021-12-31 C000536 BUTLER (PO) - OK, Distribution, , 34.5, 4.4, , 1.68,  2021-01-012021-12-31 C000536 362.16 2021-01-012021-12-31 C000536 TL81-819 SOUTHWESTERN PLANT, HOBART JCT SUB, 1, 0.22, 1, 397 ACSR, , 2021-01-012021-12-31 C000536 ferc:ElectricUtilityMember PSO-D Third Party Work Blkt 2021-01-012021-12-31 C000536 ZUNIS - OK, Distribution, , 138, 13.8, , 74.6,  2021-01-012021-12-31 C000536 ferc:ElectricUtilityMember PSO-D Third Party Work Blkt 2021-12-31 C000536 TL81-807A (RADIAL) BROKEN ARROW NORTH  TAP, , 1, 0.29, 1, 477 ACSR, 0, 0 2021-01-012021-12-31 C000536 DARLINGTON ROAD - OK, Distribution, , 138, 13.8, , 50,  2021-12-31 C000536 TL81-838B (RADIAL) 21ST & EAST AVENUE TAP, , 1, 8, 1, 556.5 ACSR, , 2021-01-012021-12-31 C000536 ORAL ROBERTS UNIVERSITY - OK, Distribution, , 138, 13.8, , 40,  2021-01-012021-12-31 C000536 (b) Fossil Fuel Steam, Generation Asset Management - Program Management 2021-01-012021-12-31 C000536 DUNCAN 138 - OK, Transmission, , 138, 69, 13.8, 90,  2021-12-31 C000536 VALLIANT 345 - OK, Transmission, , 138, 70.5, 36.2, 90,  2021-12-31 C000536 ferc:ElectricUtilityMember 4% 2021-12-31 C000536 TL81-554 PRYOR JCT SUB, GROVE, 1, 2.22, 1, 795 ACSR, 0, 0 2021-01-012021-12-31 C000536 MCALESTER CITY - OK, Transmission, , 138, 69, 13.8, 56,  2021-01-012021-12-31 C000536 TL81-537 ELK CITY SUB , ELK CITY FALCON ROAD SUB , 1, 4.4, 1, 477.0 ACSR , 0, 0 2021-01-012021-12-31 C000536 OKEMAH - OK, Distribution, , 69, 13.09, , 20,  2021-01-012021-12-31 C000536 STATION, , , 0, 0, 397.0 ACSR, 0, 0 2021-01-012021-12-31 C000536 53RD & GARNETT - OK, Distribution, , 138, 13.8, , 74.6,  2021-12-31 C000536 CYRIL - OK, Distribution, , 69, 13.8, , 8.4,  2021-01-012021-12-31 C000536 Proceeds on Capital Leaseback 2020-01-012020-12-31 C000536 ferc:ElectricPollutionControlFacilitiesMember 2021-01-012021-12-31 C000536 ferc:ElectricUtilityMemberferc:FederalInsuranceTaxMember 2021-01-012021-12-31 C000536 GRANITE - OK, Distribution, , 34.5, 13.8, , 4.2,  2021-12-31 C000536 Current and Accrued Liabilities, SWEPCO 2021-01-012021-12-31 C000536 COVID-19 Deferred Expense and Contra 2021-12-31 C000536