1. July 22, 2003

2. Corporate Overview Operations in 12 Western and Midwestern states 4 th largest combination natural gas and electricity company in the nation 4.9 million gas and electric customers Natural Gas Deliveries 396 Bcf – Annual 3.3 Bcf – Peak Day

3. Operating Companies NSP Minnesota NSP Wisconsin PSCo CLF&P SPS

4. NSP-Minnesota System Requirements MN & ND Service Area 420,000 Customers Peak Day Deliveries - 670,000 Dth Annual Deliveries – 82 Bcf Annual growth 1-2%

5. NSP-Wisconsin System Requirements WI & MI Service Area 94,000 Customers Peak Day Deliveries - 125,000 Dth Annual Deliveries – 21 Bcf Annual growth 2%

6. NSP-Generation System Requirements MN, ND, SD, MI and WI Service Territory Current Annual Gas Use – 10 Bcf Projected Annual Gas Use (2010-2015) – 20 to 40 Bcf Growth MERP 954 MW (online 2009-2010) IRP 655 MW (online 2006)

7. NSP-Minnesota & Wisconsin Typical Supply Sources by Pipeline Northern Natural Gas (NNG) Viking Gas Transmission (VGT) Great Lakes Transmission Company (GLTC) ANR Pipeline Company (ANR) Williston Basin Interstate Pipeline (WBI)

8. PSCo-LDC System Requirements Colorado Service Area Over 1 million Customers Peak Day Deliveries – 1.7 Bcf Annual Deliveries – 144 Bcf Annual growth 1-2%

9. PSCo-Generation System Requirements Colorado Service Area Peak Day Deliveries – 400,000 Dth Annual Deliveries – 65 Bcf

11. PSCo – LDC & Generation Typical Supply Sources by Pipeline Colorado Interstate Gas (CIG) Wyoming Interstate Gas (WIC) Southern Star (WNG) KinderMorgan (KM)

12. CLF&P System Requirements Wyoming Service Area 30,000 Customers Peak Day Deliveries – 40,000 Dth Annual Deliveries – 4.5 Bcf Annual growth 1-2%

13. CLF&P Typical Supply Sources by Pipeline Colorado Interstate Gas (CIG) Wyoming Interstate Gas (WIC)

14. Contacts NSP Tim CarterManager Gas Supply, Mid-Continent(303) 308-2791 Jeff IsheeGas Buyer(303) 308-2826 PSCo Sue DolanManager Gas Supply, Rockies(303) 308-6179 Craig RozmanGas Buyer(303) 308-2844 Jim LynchGas Buyer(303) 308-6118