1. WestConnect Regional Transmission Service Tariff March 16, 2015

2. WestConnect Regional Transmission Service - Status Began two-year experiment on July 1, 2009 Extended for second two-year term on July 1, 2011. Participants had filed to amend the Regional Tariff to eliminate date certain termination. –Essentially making the Regional Tariff permanent until termination is approved by the providers.

3. WestConnect Regional Transmission Service - Background Eliminates transmission rate pancaking for non- firm transactions –Continues to pancake ancillary services and losses –Retains participants’ posted OATT rates Implemented through wesTTrans platform on OASIS. Did not require FERC filing for non-jurisdictionals No state approvals required Fail-safe clause for non-jurisdictionals Revenue distributed pro-rata based on posted rates

4. Transmission Service Price Components The Regional Rate is the highest posted OATT rate in the path Ancillary Service 1 (scheduling) remains pancaked Ancillary Service 2 (reactive) assessed only at sink Losses remain pancaked –Monetized at Palo Verde Index price for date of transaction Administrative charge is a pass through of OATI charges on behalf of the transmission providers

5. WestConnect Regional Transmission Service - Participants Arizona Public Service Black Hills Colorado BH/BE Common Use System - Basin Electric Power Coop. - Black Hills Power, Inc. - Powder River Energy El Paso Electric Public Service New Mexico Southwest Transmission Cooperative Tri-State G & T Association Tucson Electric Power Western Area Power Administration - Rocky Mountain Region - Desert Southwest Region -CRSP Management Office Xcel Energy/Public Service Colorado

7. Original Experiment Parameters Risk: Without an increased number of transactions, non-firm transmission revenues could decrease for the affected Regional Participants. Performance has not dispelled the risk, but transmission providers are comfortable with offering regional transmission service.

8. Contacts and Information WestConnect (www.westconnect.com)www.westconnect.com Doug Reese – Pricing Mgmt. Comm. Chair dreese@tristategt.org 303-254-3676 Charles Reinhold – Project Manager reinhold@ctcweb.net 208-253-6916