# NORTHWESTERN CORPORATION — Yellowstone County, MT

**Citation:** NPMS FIPS 30111 / OPID 31632  
**Type / status:** inspection / current  
**Agency:** Pipeline and Hazardous Materials Safety Administration  
**Effective:** Not stated  
**Published:** 2026-07-16

68.074223 active Natural Gas pipeline miles in Yellowstone County, MT; public NPMS snapshot 2026-07-16.

## Document text

NORTHWESTERN CORPORATION (PHMSA OPID 31632) reported 68.074223 active Natural Gas pipeline miles in Yellowstone County, MT (county FIPS 30111) in the public NPMS summary snapshot dated 2026-07-16. The snapshot includes active assets only and excludes permanently abandoned assets. Exact pipeline locations and restricted NPMS GIS data are not included.

## Provenance

- Official: Yes
- Source: <https://www.npms.phmsa.dot.gov/Documents/NPMS_Active_Pipe_County_Mileage.xlsx>
- Source ID: `npms-public-summaries`
- SHA-256: `f59a2731965de891fbb01179a2a64b3d153a1f26eb5095a22d2a5a08af89b45e`
- Retrieved: 2026-08-20T04:38:11.081Z
- Exported: 2026-08-25T19:37:38.875Z
- Document slug: `npms-mileage-0a21f8dfa1c99482339ff100`

### Source metadata

```json
{
  "materialSubtype": "pipeline_mileage",
  "dataAsOf": "2026-07-16",
  "dateBasis": "data_as_of_not_publication_date",
  "fips": "30111",
  "stateFips": "30",
  "state": "MT",
  "county": "Yellowstone County",
  "region": "Yellowstone County, MT",
  "operator": {
    "id": "31632",
    "name": "NORTHWESTERN CORPORATION"
  },
  "commodity": "Natural Gas",
  "mileage": 68.07422349,
  "plantCount": null,
  "snapshotScope": "active_assets_only",
  "personalContactDataExcluded": true,
  "restrictedGisExcluded": true,
  "provenance": {
    "workbook": "pipeline_mileage",
    "sheet": "Summary - Cnty, Oper, Commodity",
    "rowNumber": 7196,
    "rowSha256": "baddf50adec48b5dc225643403edb68847e08a866b38a0352bd791644ffe7549"
  },
  "citedSections": [
    "191.29"
  ],
  "caveat": "Public aggregate snapshot only. It is not a complete representation of exact pipeline locations, may be updated, and is not an agency finding about facility condition.",
  "jurisdiction": "US",
  "operatorName": "NORTHWESTERN CORPORATION"
}
```