Gas Utilities Directory — utility profile
NorthWestern Energy Public Service Corporation d/b/a NorthWestern Energy
South Dakota · Investor-Owned · Major Regulated
Utility overview
- Utility name
- NorthWestern Energy Public Service Corporation d/b/a NorthWestern Energy
- Legal name
- NorthWestern Energy Public Service Corporation d/b/a NorthWestern Energy
- Ownership type
- Investor-Owned
- Utility class
- Major Regulated
- Rate jurisdiction
- South Dakota Public Utilities Commission
- State directory
- South Dakota utilities
- Customer classes
- Commercial, Residential
Official website and contact
- Official website
- northwesternenergy.com
- Customer service phone
- 1-888-467-2669
- Not published
Contact details are shown only where the utility publishes them.
Published state services
South Dakota
Natural gas distribution in South Dakota (~49,800 gas customers per SDPUC NG24-005 stipulation).
Customer classes: Commercial, Residential
Last confirmed: August 27, 2026
State customer informationVerification sources
- NorthWestern Energy — South Dakota Gas Rate Schedule
NorthWestern Energy · Tariff — Rate No. 81 - Residential Gas Service; Rate No. 82 - General Gas Service (accessed 2026-08-27)
- NorthWestern Energy home
NorthWestern Energy · Official Utility Website — Company identity (accessed 2026-08-27)
- SD PUC — NG24-005 Settlement Stipulation (NorthWestern Energy)
SD PUC · State Regulator Inventory — NorthWestern Energy Public Service Corporation dba NorthWestern Energy; ~49,800 SD natural-gas customers; typical residential bill impacts (accessed 2026-08-27)