Transmission planning

Each year, Tri-State develops a 10-year transmission plan that assesses future transmission needs for Tri-State’s member systems. The transmission component of this plan is developed in conjunction with West Connect and the Colorado Coordinated Planning Group (CCPG), formal regional transmission planning organizations recognized by the Western Electricity Coordinating Council (WECC).

As part of the Colorado Public Utilities Commission (COPUC), Rule 3627, Tri-State files its 10-year transmission plan with the COPUC on a biennial basis each February 1.

For more information, to send us your questions or comments regarding our transmission plans, or to be added to the stakeholder outreach list for future transmission planning meetings, please email [email protected].

Please email us your comments on Tri-State’s transmission planning to [email protected].

In your comments, please include:

  • First and last name
  • Mailing address
  • Phone number(s)
  • Name of your organization
  • Indicate if you are member of an electric cooperative, and if so, which one.
  • Please indicate which issue/project you are commenting about

Thank you for your interest.

Filing Details PUC 3627

Details included in the filing for the Colorado PUC Rule 3627 on February 1, 2026:

10-year transmission plan 2026

20-year conceptual scenario report 2026

Appendix A – Colorado transmission map

Appendix B – Denver Metro transmission map

Appendix C – Black Hills Energy transmission map

Appendix D – Black Hills Energy projects

Appendix E – Tri-State G&T 10-year transmission projects

Appendix F – Public Service Company of Colorado projects

Appendix G – Colorado Springs Utilities projects

Appendix H – Platte River Power Authority projects

Appendix I – WAPA RMR projects

Appendix J – CCPG stakeholder process

Appendix K – Public Service Company CCPG stakeholder comments

Appendix L – Black Hills CCPG stakeholder comments

Appendix M – Tri-State CCPG stakeholder comments

Appendix N – Black Hills supporting documents

Appendix O – Tri-State supporting documents

Appendix P – Public Service supporting documents

Appendix Q – How to access WECC base cases

Past filings

COPUC 3627 transmission projects and reference documents – 2024 filing

COPUC 3627 transmission projects and reference documents – 2022 filing

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