How to verify gas program and tariff changes in Montana

Montana: Trace a change from filing to the affected account

Start with FERC: interstate and intrastate pipeline responsibilities. The table below links this decision to the represented gas companies in Montana. It does not establish service or supplier availability for every account.

Keep a tariff change record

Record issuing utility, docket or filing reference, affected schedule, approval status, effective date and the first service period affected. Compare the approved sheet with the account’s actual classification.

Treat branding and enrollment separately

A company acquisition or a renamed program does not by itself establish a new price, automatic contract cancellation or eligibility at another utility. Retain customer notices and confirm the legal company and effective service rules.

Montana utility application

NorthWestern Great Falls Gas: the program detail behind this decision

NorthWestern completed the Energy West acquisition in July 2025 and transferred the operations to separate Great Falls and Cut Bank gas subsidiaries, according to its SEC disclosure. The Great Falls operating tariff matters; a tariff for NorthWestern’s other Montana gas business is not automatically the correct schedule. Nwe Greatfalls Acquired; Nwe Greatfalls Rates.

Apply the evidence to an account file

Match a proposed or approved change to NorthWestern Great Falls Gas commercial schedule. Reopen the effective company reference and confirm Current operating company and any qualified transportation arrangement instead of importing a rule from another service company.

A change log with an explicit implementation gate

Use a row for the company, source URL, document type, schedule, status, approval date, effective date, affected accounts and action owner. A proposed sheet can inform a sensitivity scenario while remaining outside the effective budget. After approval, verify the final sheet rather than assuming the requested amount survived. For an ownership change, attach the service notice and identify any separate legacy rate areas. Retain the prior reference for earlier billing periods so corrections can be checked against the right rules.

Turn the review into a calculation

Plan notice and enrollment milestones. The planner uses your calendar-day inputs and does not send notices or confirm a utility enrollment date.

Read the Montana utility guide for the wider service-company distinctions. Convert billed gas units using the bill’s heat-content factor when moving from volume to energy.