Wyoming Pipeline Authority August 30, 2005

1. Wyoming Pipeline Authority August 30, 2005 Gaylen Haag Business Development Questar Pipeline Company

2. Questar Gas cities served Questar Gas system Questar Pipeline system In the Heart of the Rockies Principal producing basins Overthrust WYOMING Pipeline Questar Pipeline IDAHO OVERTHRUST Preston GREEN RIVER NEVADA Rock Springs SKULL CREEK Evanston Wamsutter Clay Basin SAND WASH Salt Lake City Kern River UINTA PICEANCE TransColorado PARADOX UTAH COLORADO SAN JUAN CALIFORNIA Southern Trails Western Section Eastern Section Long Beach

3. Questar Pipeline Expansion Projects

4. New Expansion Projects • Overthrust Pipeline Tie to Kern’s Painter Lateral • Overthrust Pipeline Expansion to Opal • Extension to Bison Pipeline • Storage Projects • Rock Springs • Southwest Wyoming Salt Cavern Storage • Southern System Expansions to Goshen • Southern System Expansions to Greasewood / Meeker

5. Overthrust Pipeline Company Proposed Interconnect with Kern at the Painter Lateral QPC JL90 Kern WIC QPC Eakin Station QPC Kanda Overthrust Pipeline Questar Pipeline NPC New interconnect with Kern River’s Painter Lateral 200,000 Dth/day, available January 1, 2006 (Sold out on August. 26.) Receipt Points: WIC, CIG & QPC @ Kanda, Granger Plant & Clear Creek Storage

6. Overthrust Expansion to Opal Northwest Pipeline Opal QPC JL90 Overthrust extension to Opal WIC Blacksfork /Granger QPC Kanda Overthrust Pipeline Kern Questar Pipeline 500,000 Dth/day expansion to Opal (West) Deliveries to Northwest Pipeline and Kern River to go west. 500,000 Dth/day from the Opal Plant to Kanda (East) Deliveries to WIC & CIG @ Kanda to go east.+ Open Season September / October 2005. In service 4th quarter 2007

7. North Dakota Montana Bismarck Northern Border Pipeline Bison Pipeline Powder River Basin South Dakota Gillette Wyoming Wind River Basin Wamsutter Pipeline Rock Springs Salt Lake City Wamsutter Nebraska Cheynne Questar Pipeline System Kern River Utah Colorado Wamsutter Pipeline - Extension to Bison To Midwest Markets NNG, NGPL, Chicago ANR, Vector, Midwestern, Guardian, etc. 245 mile Pipeline from Wamsutter to Bison Pipeline 500,000 Dth/day Wamsutter receipts: Gas Plants (ie. Echo Springs), WIC, CIG, Entrega, Southern Star, Wamsutter area gathering,Lost Creek Lateral etc. Avoids congested routes to Mid-continent.

8. Rock Springs Storage Project • Potential development of traditional gas storage in the Rock Springs, Wyoming Area • 19 Bcf working gas capacity • Proposed ties to QPC, CIG, and WIC, at Kanda, Kern via Overthrust and Overland Trail • Estimated in-service date: Two years after contract commitments WYOMING GREATER GREEN RIVER WAMSUTTER COLORADO FERRON UTAH

9. Southwest Wyoming Salt Cavern Storage Project WYOMING • Near Evanston, Wyoming • Ultimate capability 12.5 Bcf working gas – initially 5 Bcf • Potential deliverability of 500 MMcf/day with 5 Bcf of working gas • Increased interest with additional electrical generation markets • Interconnects with QPC and Kern River with potential tie to Overthrust Pipeline GREATER GREEN RIVER Overthrust Pipeline WAMSUTTER COLORADO FERRON UTAH

10. Current Southern System Expansion Project WYOMING Questar Gas Monument Buttes Questar Gas Power Markets Clay Basin Greasewood Blind Canyon JL 47 ML 80 Oak Spring ML 59 ML 40/41 ML 40 ML 103/68 Divide Creek CIG101 ML 104 ML 104 Thistle Creek Fidlar Ferron Kern River at Goshen • 2005 Southern System Expansion • 18.7-mile extension of ML 104 • Two new compressor stations and modification of existing compression • 102,000 Dth/d, fully subscribed • Projected in-service date of Nov. 1, 2005 Existing Interconnects Compression Facilities

11. Future Southern System Expansion Options to Goshen WYOMING Soldier Creek Questar Gas Monument Buttes Questar Gas Clay Basin Power Markets Greasewood Blind Canyon JL 47 ML 80 Oak Spring ML 59 ML 40/41 ML 40 ML 103/68 Divide Creek CIG101 ML 104 ML 104 Thistle Fidlar Kern River at Goshen Ferron Existing Interconnects • Option 1: Proposed 38-mile ML 104 extension • 100,000 Dth/d • Option 2: Proposed 65-mile ML 104 extension • 180,000 Dth/d Compression Facilities • $.26 Dth/d rate with 10-year minimum term • Target Nov. 2007 in-service date with 2005 commitments

12. Spanning the West