Designated Network Loads and Resources Load Served by Company Owned Resources

1 Designated Network Loads and Resources Load Served by Company Owned Resources

NWMT Point of Receipt Firm Point of Delivery for Load to Contracted Entity Location Network Resources (POR) be Served Resource Owner Desig. MW Load MW Specified Designation Period Notes NorthWestern Energy - retail supply load NorthWestern System Basin Creek BASINCREEK NWMT.SYSTEM Basin Creek 52 unspecified - 07/01/2036 BGI BGI NWMT.SYSTEM Yellowstone Energy Partners 60 07/01/2013 -12/01/2028 Limited Black Eagle BLACKEAGLE NWMT.SYSYTEM NorthWestern Energy 5 8/1/2017 - 8/01/2042 Black Eagle BLACKEAGLE GTFALLSNWMT NorthWestern Energy 17 11/18/2014 - 08/01/2039 Black Eagle Solar QFS GTFALLSNWMT Black Eagle Solar LLC 3 07/01/2017 - 07/01/2042 Broadview East Wind, QF QFS NWMT.SYSTEM Two Dot Wind, LLC 1.6 07/01/2018 - 07/01/2043 Broadwater Dam BROADWATER NWMT.SYSTEM Montana DNRC 10 09/01/2013 - 12/01/2028 Colstrip 3 & 4 COLSTRIP NWMT.SYSYTEM NorthWestern Energy 222 12/29/2010 - 9/1/2037 Crooked Falls - (Ryan, Morony, CROOKEDFALLS NWMT.SYSTEM NorthWestern Energy 81 08/01/2017 - 8/01/2042 Cochrane, Rainbow) Crooked Falls - (Ryan, Morony, CROOKEDFALLS GTFALLSNWMT NorthWestern Energy 130 11/18/2014 - 08/01/2039 Cochrane, Rainbow) Crooked Falls - (Ryan, Morony, CROOKEDFALLS Great Falls NorthWestern Energy 40 06/01/2017 - 06/01/2042 Cochrane, Rainbow) TEA PPA CROSSOVER NWMT.SYSTEM The Energy Authority 25 08/01/2021 - 08/01/2024 Fairfield Wind FAIRFIELD GTFALLSNWMT Fairfield Wind, LLC 10 01/01/2014 - 01/01/2039 Flint Creek Hydro QFS NWMT.SYSTEM Flint Creek Hydroelectric, LLC 2 12/01/2012 - 12/31/2037 Green Meadow Solar, QF QFS NMWT.SYSTEM Green Meadow Solar 1, LLC #179 3 12/01/2016 - 12/01/2041

Greenfield Wind GREENFIELD GTFALLSNWMT Greenfield Wind LLC 25 12/1/2015 - 12/1/2040 Big Timber Wind BIGTIMBER NWMT.SYSTEM Big Timber Wind, LLC 25 1/1/2018 - 6/30/2043 Gordon Butte, QF GORDONBUTTE NWMT.SYSTEM Gordon Butte Wind, LLC 10 12/01/2011 - 12/01/2036 Gordon Butte, QF GORDONBUTTE NWMT.SYSTEM Gordon Butte Wind, LLC 9 03/01/2019 - 12/01/2036 Great Divide Solar QFS NWMT.SYSTEM Great Divide Solar LLC 3 07/01/2017 - 07/01/2042 Hauser HAUSER NWMT.SYSTEM NorthWestern Energy 19 11/18/2014 - 08/01/2039 Holter HOLTER NWMT.SYSTEM NorthWestern Energy 48 11/18/2014 - 08/01/2039 Judith Gap JUDITHGAP NWMT.SYSTEM InVenergy 135 10/01/2013 - 12/01/2025 Lower South Fork QFS NWMT.SYSTEM Lower South Fork LLC 1 12/01/2012 - 12/31/2037 Madison MADISON NWMT.SYSTEM NorthWestern Energy 13 03/01/2021 - 08/01/2039 Magpie Solar QFS NWMT.SYSTEM Magpie Solar LLC 3 07/01/2017 - 07/01/2042 Meadowlark Solar MEADOWLARK NWMT.SYSTEM Energy of Utah 20 10/01/2021 - 10/01/2036 Mill Creek Generating Station DAVEGATES NWMT.SYSTEM NorthWestern Energy 155 1/1/2011 - 1/1/2051 Increasing to 218 1/1/2023 - 1/1/2048 Montana Sun MTSUN NWMT.SYSTEM MT Sun Solar, LLC 80 07/01/2022 - 07/01/2047 Montana 1 MT1 NWMT.SYSTEM Colstrip Energy Partners Limited 35 07/01/2013 -12/01/2028 Morgan Stanley PPA BPAT.NWMT NWMT.SYSTEM Morgan Stanley 50 10/01/2021 - 07/01/2024 Musselshell Wind, QF MUSSELSHELL NWMT.SYSTEM Musselshell Wind Project, LLC 20 12/31/2012 - 12/31/2037 Mystic MYSTIC NWMT.SYSTEM NorthWestern Energy 12 11/18/2014 - 08/01/2039 Powerex PPA BPAT.NWMT NWMT.SYSTEM Powerex (BC Hydro) 100 01/01/2023 - 01/01/2028 Powerex PPA BPAT.NWMT NWMT.SYSTEM Powerex 60 02/01/2021 - 01/01/2024 Qualifying Facilities Various NWMT.SYSTEM Various 2 7/1/2013 - 12/01/2028 River Bend Solar, QF QFS NWMT.SYSTEM River Bend Solar, LLC #203 2 12/01/2016 - 12/01/2041 South Mills Solar 1, LLC QFS NWMT.SYSTEM South Mills Solar 1, LLC 3 12/01/2016 - 12/01/2041 Spion Kop SPIONKOP GTFALLSNWMT NorthWestern Energy 40 11/01/2012 - 11/01/2037 South Peak Wind SOUTHPEAK GTFALLSNWMT South Peak Wind, LLC 80 12/01/2019 - 12/01/2034 Stillwater Wind STILLWIND NWMT.SYSTEM Stillwater Wind, LLC 80 09/01/2018 - 08/01/2043 Thompson Falls TFALLS NWMT.SYSTEM NorthWestern Energy 94 11/18/2014 - 08/01/2039 Tiber Montana WAPA WAPA BA Tiber Montana 7 unspecified - 2024 Two Dot Wind, QF TWODOT NWMT.SYSTEM NorthWestern Energy 10 01/01/2013 - 12/31/2037 Turnbull Hydro TURNBULL GTFALLSNWMT Turnbull Hydro 13 4/1/2011 - 4/1/2031 Ash Grove Cement Company Clancy, Montana Kerr KERR NWMT.SYSTEM Energy Keepers Inc. 6 7 01/01/2021 - 01/01/2025 Aspen Air US, LLC Billings, MT Colstrip COLSTRIP NWMT.SYSTEM Talen 7 11 05/01/2021 - 01/01/2023 Basin Electric Southeastern Montana Off System resource YTP NWMT.SYSTEM WAPA 8 11/01/2017 - 01/01/2022 Morgan Stanley PPA BPAT.NWMT NWMT.SYSTEM Morgan Stanley 125 196 01/01/2019 - 01/01/2022 Morgan Stanley PPA BPAT.NWMT GREATFALLS Morgan Stanley 15 196 01/01/2022 - 01/01/2028 Central Montana Morgan Stanley PPA BPAT.NWMT NWMT.SYSTEM Morgan Stanley 133 196 01/01/2022 - 01/01/2028 Morgan Stanley PPA BPAT.NWMT GTFALLSNWMT Morgan Stanley 2 196 01/01/2022 - 01/01/2028 Colstrip COLSTRIP NWMT.SYSTEM Macquarie Energy 50 05/01/2022 - Fort Peck GREATFALLS NWMT.SYSTEM WAPA 29 11/01/2015 - 1/1/2026 Barretts Minerals Dillion, MT Kerr KERR NWMT.SYSTEM Energy Keepers Inc. 4 6 07/01/2021 - 11/01/2021 Barretts only designates in 4 month increments Beartooth Electric Cooperartive Redlodge, MT Fort Peck GREATFALLS NWMT.SYSTEM WAPA 2 18 01/01/2021 - 01/01/2026 Beartooth Electric Cooperartive Redlodge, MT Kerr KERR NWMT.SYSTEM Energy Keepers Inc. 8 18 10/1/2022 - 10/01/2027 Benefis Health Systems Great Falls MT Kerr KERR GTFALLSNWMT Energy Keepers Inc. 4 7 7/1/2019 to 6/30/2022 Big Horn County Electric Cooperative Southeastern Montana Fort Peck GREATFALLS GTFALLSNWMT WAPA 3 18 09/01/2018 - 07/01/2023

6/29/2021 2 Designated Network Loads and Resources Load Served by Company Owned Resources

NWMT Point of Receipt Firm Point of Delivery for Load to Contracted Entity Location Network Resources (POR) be Served Resource Owner Desig. MW Load MW Specified Designation Period Notes Bonneville Power Administration (one each for Glacier, The 5 BPA Coop loads located Federal Columbia River Power BPAT.NWMT NWMT.SYSTEM BPA 147 10/01/2011-09/30/2028 Missoula, Northern Lights, Ravalli, and Vigilante Coops) throughout western Montana System (Glacier 37.7 MW, Missoula 56.8 MW, Northern Lights 2.7 MW, Ravalli 42.4 MW, Vigilante 44.2 MW)

The Glacier Electric Coop load GTFALLSNWMT BPA 38 10/01/2011-09/30/2028 located near Cutbank, MT Regulation BPAT.NWMT NWMT.SYSTEM 5 03/01/2017 - 02/01/2028

Spin and Non-Sping self supply BPAT.NWMT NWMT.SYSTEM 6 06/01/2020 - 02/01/2028

Calumet Refining, LLC Great Falls, Montana Colstrip COLSTRIP GTFALLSNWMT Talen 14 25 10/01/2021 - 10/01/2026 CHS Inc. Laurel Montana Morgan Stanley PPA MATL.NWMT NWMT.SYSTEM, GTFALLSNWMT Morgan Stanley 25 58 7/01/2019 - 7/01/2024 City of Great Falls Great Falls, MT Kerr KERR GTFALLSNWMT Energy Keepers Inc. 4 6 11/1/2018 - 11/1/2023 Colstrip Steam Electric Station Nichols Pump near Colstrip Colstrip 3 & 4 COLSTRIP NWMT.SYSTEM Avista Corp 9 10 3/1/2017 - 11/1/2021 CryptoWatt Mining, LLC Butte, Montana Tenaska PPA BPAT.NWMT NWMT.SYSTEM Tenaska 67 75 09/01/2020 - 09/01/2021 ExxonMobil Corporation Billings Montana Colstrip COLSTRIP NWMT.SYSTEM Talen 35 35 8/1/2018 - 8/1/2023 General Mills Operations, LLC Great Falls MT Colstrip COLSTRIP GTFALLSNWMT Talen 2 4 5/1/2020 - 10/1/2022 Great Falls Public Schools Great Falls MT KERR KERR GTFALLSNWMT Energy Keepers Inc. 3 3 01/01/2021 - 12/31/2025 GCC Three Forks, LLC Three Forks, Montana Kerr KERR NWMT.SYSTEM Energy Keepers Inc. 6 8 03/01/2020 - 03/01/2025 Magris Talc USA Three Forks, Montana Kerr KERR NWMT.SYSTEM Energy Keepers Inc. 3 6 05/01/2021 - 01/01/2024 Montana Resources Butte, Montana Energy Keepers PPA BPAT.NWMT NWMT.SYSTEM Energy Keepers Inc. 43 50 01/01/2022 - 06/01/2023 38 06/01/2023 - 11/01/2023 43 11/01/2023 - 01/01/2027 Montana Resources Butte, Montana Colstrip COLSTRIP NWMT.SYSTEM Talen 43 50 01/01/2017 - 01/01/2022 Montana Resources Butte, Montana Kerr KERR NWMT.SYSTEM Energy Keepers Inc. 3 01/01/2020 - 01/01/2026 Phillips 66 Company Various Shell PPA BPAT.NWMT NWMT.SYSTEM PPA Shell 41 55 7/1/2020 - 07/01/2023 Phillips 66 Company Various Shell PPA BPAT.NWMT GTFALLSNWMT PPA Shell 14 7/1/2020 - 01/01/2023 HyperBlock, LLC Bonner, Montana Kerr KERR NWMT.SYSTEM Energy Keepers Inc. 19 20 06/01/2019 - 09/01/2022 39MW Permanently Terminated Town of Philipsburg Philipsburg, Montana Town of Philipsburg Generation NWMT.SYSTEM Town of Philipsburg 0.2 0.13 10/1/2015 - 10/1/2040 REC Butte, Montana Shell PPA BPAT.NWMT NWMT.SYSTEM Shell 75 117 02/01/2021 - 12/31/2021 June 2021 38MW only Roseburg Forest Products Missoula, Montana Colstrip COLSTRIP NWMT.SYSTEM Talen 6 8 11/01/2020 - 10/01/2022 Suiza Dairy Group (Meadow Gold) Colstrip COLSTRIP GTFALLSNWMT Talen 1 2 10/01/2014 - 10/01/2023 Colstrip COLSTRIP NWMT.SYSTEM Talen 1 10/01/2014 - 10/01/2023 Stillwater Mining Company Columbus and Nye, Montana Kerr KERR NWMT.SYSTEM Energy Keepers Inc. 31 34 07/01/2019 - 07/01/2022 Western Area Power Administration (WAPA) Dodson, Toston, Fort Belknap and Various WAPA System Resources* CROSSOVER GREATFALLS NWMT.SYSTEM WAPA 4 Hammond, Montana Bozeman, MT FTPECKWEST (off system WAPA GREATFALLS NWMT.SYSTEM WAPA 4 4 03/01/2021 - 06/01/2030 resource) Great Falls, MT FTPECKWEST (off system WAPA GREATFALLS GTFALLSNWMT WAPA 4 4 08/01/2021 - 01/01/2046 resource) *Off System Resource **Note: Short Term Designations should be viewd on the NITS on OASIS Module, as they are not included on this sheet

6/29/2021 Resource Data NorthWestern Energy (NWMT) The information below contains nameplate data for generators that have all or part of the unit designated by a Network Transmission Customer. Actual MW amounts designated are displayed under the Designated Network Loads and Resources document

Resource Geographic Resource Resource Name Resource Type Location Resource Electrical Location Capacity Company Owned Generation Facilities Colstrip 4 (NWE's Share) Thermal Rosebud Colstrip 500 kV 222.00 Dave Gates Generating Station Thermal Deer Lodge Mill Creek 230 kV 218.00 Black Eagle Hydro Cascade Great Falls Riverview 100 kV 22.00 Cochrane (Great Falls Hydro) Hydro Cascade Rainbow 100 kV 70.00 Hauser Hydro Lewis & Clark East Helena 69 kV 18.00 Holter Hydro Lewis & Clark Canyon Crk to Wolf Crk 100 kV 53.00 Madison Hydro Madison Harrison to Cobblestone 100 kV 11.00 Mystic Hydro Stillwater Line Creek 50 kV 12.00 Morony (Great Falls Hydro) Hydro Cascade Great Falls 100 kV 49.00 Rainbow (Great Falls Hydro) Hydro Cascade Rainbow 100 kV and 69 kV 61.00 Ryan (Great Falls Hydro) Hydro Cascade Rainbow 100 kV 60.00 Spion Kop Wind Judith Basin 100 kV line Raynesford 40.00 Thompson Falls Hydro Sanders Thompson Falls 115 kV 98.00 Two Dot Wind Wheatland 10.00

Contracted Generation Facilities Basin Creek Thermal Silverbow Butte MHD 161 kV 51.80 Basin Electric Power Contract Basin Electric Various, with delivery to WAPA Transmission System Various Power Cooperative Crossover POD on the Resources NorthWestern System BPA Off-System Contracts BPA Federal Washington and Oregon WAPA Transmission System Various Columbia River Power System Canyon Ferry Hydro Lewis & Clark Canyon Ferry 100 kV 58.00 Colstrip 1, 2, 3 4 (Other Partner's Share)* Thermal Rosebud Colstrip 500 kV 1,346.00 Colstrip 3 (PPL's Share) Thermal Rosebud Colstrip 500 kV 222.00 Hardin Thermal Big Horn Hardin Auto 230 kV 109.00 Judith Gap Wind Wheatland Judith Gap South 230 kV 135.00 Kerr (SKQ) Hydro Lake Kerr 115 kV and 161 kV 208.00 Tiber Hydro Liberty 115kV bus Tiber (WAPA) 7.00 Turnbull Hydro Hydro Teton Turnbull Sub 69 kV near Bole Tap 13.00

Qualifying Facilities 6/29/2021 71 Ranch Wind Wind Wheatland 100 kV at Gordon Butte Substation 3.00 Barney Creek Hydro Park Pine Creek REA (PEC) 69 kV 0.06 Billings Generation, Inc. Thermal Yellowstone Billings Exxon 50 kV 60.00 Black Eagle Solar LLC Solar Cascade 4.5 Miles NE of Great Falls, MT 3.00 Boulder Hydro Hydro Granite Philipsburg 50 kV 0.51 Broadwater (Toston) Dam Hydro Broadwater Broadwater 100 kV 10.00 Broadview East Wind Wind Yellowstone 3 miles E. of Broadview, MT on 21 Mile Rd 2.00 Cascade Creek Hydro Park S of Livingston, MT on Cascade Creek 0.07 Colstrip Energy Limited Partnership (Montana Thermal Rosebud Montana One 115 kV 35.00 One) DA Wind Wind Wheatland 100 kV at Gordon Butte Substation 3.00 Fairfield Wind Wind Teton Fairfield Wind Substation 69 kV 1.5miles East 10.00 WAPA Bole Substation Flint Creek Hydro Hydro Granite Distribution system near Philipsburg 2.00 Gordon Butte Wind Wheatland 100 kV line Groverland 10.00 Great Divide Solar LLC Solar Lewis & Clark 1 Mile NE of Canyon Creek, MT 3.00 Green Meadow Solar Lewis & Clark 7330 Green Meadow Drive, Helena 3.00 Greenfield Wind Wind Teton Rainbow - Bole 69kV 25.00 Big Timber Wind Wind Sweet Grass Big Timber 161 Kv 25.00 Hanover Hydro (Jenni Hydro) Hydro Fergus Hanover 50 kV 0.24 Lower South Fork Hydro Carbon 50kV line near Red Lodge 0.46 Magpie Solar LLC Solar Golden Valley 2 Miles SE of Lavina, MT 3.00 Meadowlark Solar Solar Yellowstone 161kV at Alkali Creek Substation Montana Marginal Energy Wind Park Downer 50 kV 0.20 Musselshell Wind Wind Wheatland 100 kV line Harlotown 20.00 Oversight Resources Wind Wind Wheatland 100 kV at Gordon Butte Substation 3.00 Pine Creek Hydro Park 9 mi. S of Livingston on Pine Creek 0.30 Pony Generating Station Hydro Madison 100kV bus Harrison-Pony 0.30 River Bend Solar Stillwater Pill Hill Road, Reed Point, MT 2.00 Ross Creek Hydro Gallatin 50kV Bus Belgrade 0.45 South Dry Creek Hydro 100kV bus Two Dot 1.20 South Mills Solar 1, LLC Solar Big Horn South Mills Rd., Hardin MT 3.00 South Peak Wind Wind On Broadview to Great Falls 230kv near 80.00 Spion Kop, MT Strawberry Creek Hydro Park 15 mi. S of Livingston on Strawberry Creek 0.19 Cycle Power Partners (Horseshoe Bend) Wind Cascade 100kV line near Great Falls Northwest 9.00 Substation Wisconsin Creek Ptn Hydro Madison Distribution system near Sheridan, MT 0.40 Stillwater Wind Wind Stillwater 230 between Wilsall and Shorey Rd. 80.00 * This represents the following partners share: Portland General Electric, PacifiCorp, Avista Corporation and Puget sound Energy.

6/29/2021