Northern Natural Gas Company

1. Western Canadian Basin Rocky MountainBasins Northern Natural Gas Company Extensive Access to Major Utilities and Industrials in the Upper Midwest Flexible Operations • Interconnections with 4 Major Pipelines in Market Area • Storage Capacity of 56 Bcf • Bi-Directional Flow Capabilities Over 85% of Revenues Comprised of Demand Charges 95% of Market Area Capacity Contracted Through 2003 No New Rate Case Until November 2003 Montana Minnesota North Dakota Michigan 1.3 Bcf/d Wisconsin South Dakota Wyoming .3 Bcf/d Market Area Nebraska Iowa Illinois Kansas Hugoton Basin Supply Area Missouri Oklahoma Anadarko Basin New Mexico 1.9 Bcf/d Market Area Volumes(BBtu/d) Permian Basin Enron Assets December Full Year 3,483 Storage Texas 2,775 Northern Natural Pipeline 2,173 2,202 Major Pipeline Interconnects Great Lakes Viking Northern Border Trailblazer 1999 2000 1999 2000 2000 Average Flows

2. 2001 2002 2003 Storage 372 MW 150 MW Northern Natural Gas CompanyMarket Area Initiatives Completed Agreement Minnesota Great River Energy Peaking Plant May 2001 In-Service Michigan 275 MW 463 MW Customer Profile Gas-Fired Merchant Plant 120 MMcf/d Peak Requirement Situated Close to Main Pipeline Enron Solution No-Notice, Flexible Supply Average Service of 50 MMcf/d Peak Use 2.4 Times Average 3-Year Term Enron Benefits Adds Demand During Off-Peak, Summer Season Establishes Long-Term Customer Wisconsin 250 MW South Dakota 445 MW 200 MW 500 MW 300 MW Nebraska Iowa 372 MW Market Area Illinois Kansas Missouri Supply Area 3,000 MW of Gas-Fired Power Plants Under Development in Close Proximity to Northern’s System Innovative Tariffs in Place to Provide Flexible Gas Supply-Related Services