Intertie BPA meters and publishes flows for, WECC Path 8. Drawn as the 4 BPA lines that make up the cut. A metered cut plane, not a single wire.
2026-09-18
BPA's published TTC series for the path (mode over the 30-day OPI window) or the WECC path rating where BPA publishes none; a directional operating limit, not a sum of line ratings
2026-09-18 · reported · curated · valid · final
BPA OPI TTC series 2026-08-18..09-17: E-W TTC mode 2,200 MW (range 1,506-2,200); WECC Path 8 accepted rating 2,200 MW E-W / 1,350 MW W-E
bpa_paths.csv; path_id=montana-pacific-nw; source=https://www.wecc.org/sites/default/files/documents/progress_report/2026/2026%20Path%20Rating%20Catalog%20Public.pdf
Publisher & attribution ↗ Cite this released fact ↗From Broadview / Mill Creek / Ovando / Rattlesnake / Kerr (NWE Montana) to Garrison / Hot Springs / Kalispell (BPA). Sign convention: west to east positive (E-W TTC series negative; typical E-W flow reads negative). Drawn as the named BPA lines
BPA publishes this path in its OPI CSV (15-minute); not yet collected live
Curated from WECC, reviewed 2026-09-18.
Partial: WECC Path 8 cut plane also has Mill Creek-Garrison 230, Mill Creek-Anaconda (BPA) 230, Ovando-Garrison 230, Placid Lake-Hot Springs 230, Rattlesnake-Dixon 230, Thompson Falls-Burke 115, Crow Creek-Burke 115 (none in BPA line file; BPA file has Garrison-Anaconda No 1 and Hot Springs-Rattlesnake No 1 which are not verified as the same circuits); BPA 2025 Transmission Plan 10.4 lists the Rattlesnake 230/161 kV transformer instead of Rattlesnake-Garrison; BPA monthly file 2012-01 labels PI 36920 'NWE-PNW' Montana cutplane; ATCID V88 rates the separate West of Garrison 1:1 path at the Path 8 rating A path is a metered cut plane; its TTC is a directional operating limit for the whole path, never a rating of any single line, and flow on it is not attributable to one line.
Path definitions from BPA's OPI Paths page, ATCID V88 and 2025 Transmission Plan; ratings from BPA's OPI TTC series and the WECC 2026 Path Rating Catalog
A path is a metered cut plane; member lines are those BPA names, so partial cuts (non-BPA lines) are noted per row. TTC is a directional operating limit on the review date, not a rating of any line.
Bonneville Power Administration, Geospatial Services
This product was made for informational purposes only and was created with the best available data at time of production. It does not represent any legal information or boundaries. BPA GIS disclaims responsibility or liability for any data discrepancies or errors. No BPA endorsement; no engineering or rights-of-way use. Operating voltage is retained raw only; the source declares no unit.
Release 20260929T050546Z-51ae0f7d3c78 · Record JSON