Bill Barrett (BBG) 8-K Regulation FD Disclosure

Howard Weil Energy Conference April 4, 2005 Bill Barrett, CEO

Except for the historical information contained herein, the matters discussed in this presentation are forward-looking statements. These forward-looking statements reflect our current views with respect to future events, based on what we believe are reasonable assumptions. These statements, however, are subject to risks and uncertainties that could cause actual results to differ materially including, among other things, market conditions, oil and gas price volatility, uncertainties inherent in oil and gas production operations and estimating reserves, unexpected future capital expenditures, competition, the success of our risk management activities, governmental regulations and other factors discussed in our Registration Statement on Form S-1 and Annual Report on Form 10-K for the year ended December 31, 2004 filed with the Securities and Exchange Commission (SEC). We refer you to the "Cautionary Note Regarding Forward-Looking Statements" section of the Registration Statement and Form 10-K. Forward-Looking Statements

Corporate Office: Denver, Colorado Founded 2002 IPO December 9, 2004; NYSE symbol BBG 140 employees Technical staff includes: 12 Geologists 4 Geophysicists 16 Petroleum Engineers 6 Landmen 2 Environmental/Regulatory Specialists Bill Barrett Corporation Summary Information

Williston Piceance Powder River Uinta Wind River 6 6 21 17 41 Investment In Our Asset Base December 2004 Production (MMcfe/d) Williston 6 Piceance 6 Powder River 21 Uinta 17 Wind River 41 Production (MMcfe/d) 2002 2002 2003 2003 2004 Drilling 23.7 30.7 47 71.7 91 Mar 2002 Dec 2002 June 2003 Dec 2003 Dec 2004 24 31 47 73 91 63% Compounded Annually Record Of Growth 2002 2002 2003 2003 2004 Drilling 58 130 159 204 292 Mar 2002 Dec 2002 June 2003 Dec 2003 Dec 2004 292 130 58 204 159 Net Proved Reserves (Bcfe) 80% Compounded Annually Reserve Replacement (Percent) 2003: 565% 2004: 378%

Net Undeveloped Acres Record Of Growth East 46 160 667 765 939 Mar 2002 Dec 2002 Dec 2003 June 2004 173% Compounded Annually Mar 2005 939 765 667 160 46 1,600,000+ Gross 939,000+ Net (thousands)

Wind River Powder River-CBM Williston Other Piceance Uinta 56 20 9 5 120 66 Piceance 44% Uinta 24% Wind River 20% Powder River CBM 7% Development Exploration Acreage G&G Other Facilities 211.3 27.8 7.8 5.1 2.4 21.6 Exploration 10% Development 76% 2005 Capex $276 MM Williston 3% Other 2% Other 1% Facilities 8% Acreage 3% G&G 2%

Pure Rockies exploration and production company focused primarily on natural gas Extensive multi-year development drilling inventory Exposure to multiple high impact, high return exploration plays Heavily weighted towards unconventional projects: low risk, repeatable, long life, large reserve size Utilize cutting-edge technology Achieved strong production and reserve growth Strong balance sheet positioned for growth Experienced management team and technical staff with demonstrated exploration expertise Key Investment Highlights

Denver, CO Big Horn Basin Powder River Basin Green River Basin Uinta Basin Piceance Basin Paradox Basin Williston Basin DJ Basin Wind River Basin Big George CBM Horizontal Oil Key Areas of Operation Key Take-Away Points 12 core producing/ development areas 24 exploration projects 369 wells in 2005 Conventional Biogenic Gas, Fractured Shale, Conventional Oil Basin Centered Tight Gas Gas Prone Area Oil Prone Area Project Area Conventional Conventional Tight Gas Sandstone, CBM Basin Centered Tight Gas, Conventional Oil Fractured Shale

Grand White River Uplift SCALE: 1 Township = 36 sq mi Rifle, CO 10 MMcfe/d Net Production (Feb. 2005 ) 22,101 Gross / 17,187 Net Acres (Mar. 2005) 89 Bcfe Est. Proved Reserves (Dec. 31, 2004) $120 MM Capex 2005 (95 Wells, 12 re-completes) Piceance Basin Basin Centered Gas Project - Gibson Gulch Hogback Grand Valley 233 Bcfe 130 MMcfed Rulison 275 Bcfe 128 MMcfed Parachute 139 Bcfe 88 MMcfed Mamm Creek 259 Bcfe 271 MMcfed Divide Creek 65 Bcfe 2 MMcfed Barrett Acreage Gas Producing Area Pipeline CIG 16" Questar GVGS Northwest Gibson Gulch COLORADO Piceance Basin

E = Exploratory wells D = Development wells = Key information/results available Basin Centered Gas Project 10-Acre Density Approved January 10, 2005 Silt Gibson Gulch Unit Scale: 640 ac = 1 Mile (with 10 ac grid) COLORADO Piceance Basin Grand Hogback Mamm Creek Field 271 MMcfed Gibson Gulch, Piceance Basin Barrett Exploratory Wells 2005 2006 BASIN Q1 Q2 Q3 Q4 Q1 Q2 AREA Gibson Gulch Piceance E 2 wells DRILLING SCHEDULE D on-going 95 well program (5-6 rigs) Barrett Acreage Gas Producing Area Joint Ownership Areas Gibson Gulch Unit Barrett Wells Mesaverde Structure

San Arroyo 381 Bcfe Monument Butte 289 Bcfe Natural Butte 2 Tcfe Altamont/Bluebell 3.1 Tcfe Drunkards Wash 278 Bcfe West Tavaputs Garmesa Lake Canyon Price, UT Hill Creek Tumbleweed Cedar Camp Brundage Canyon Roosevelt, UT 16 MMcfe/d Net Production (Feb. 2005) 49 Bcfe Est. Proved Reserves (Dec. 31, 2004) $66 MM Capex 2005 (23 Wells, 6 re-completes) UTAH Uinta Basin Trend Garmesa SCALE 1 Township = 36 sq mi Uinta Basin

E = Exploratory wells D = Development wells = Key information/results available 3D = 3D seismic survey SCALE 1 Township = 36 sq mi Barrett Acreage Gas Well Oil Producers San Arroyo 381 Bcfe Hill Creek WI 37.5 - 75% Trend Garmesa Uinta Basin Drilling BBC #1-6NHC 3.5 MMcfe/d BBC #3-6NHC 10 MMcfe/d Garmesa Project West Tavaputs 8,217 Net Undeveloped Acres 2005 2006 BASIN Q1 Q2 Q3 Q4 Q1 Q2 AREA Tumbleweed D Uinta Cedar Camp E 2 wells E 3D DRILLING SCHEDULE Cedar Camp 16 sq mi 3D WI 37.5 - 80% Tumbleweed 20 sq mi 3D WI 38.66% WOCT Cedar Mountain 2 Bcf & 5 Bcf

E = Exploratory wells D = Development wells = Key information/results available 2005 2006 BASIN Q1 Q2 Q3 Q4 Q1 Q2 AREA W. Tavaputs E Uinta Scale: 640 ac = 1 Mile (with 40 ac grid) West Tavaputs Project Barrett Acreage Seismic Option Acreage Gas Well 2005 Location 3-D Seismic Outlines Existing Pipelines Proposed Pipelines Getty Deep Well (1980) Tested: Dakota 315 Mcf Entrada 1,800 Mcf 83 Sq Mile 3-D Survey WOC WOC Deep Test WOC Completing Deep Well (1967) 46,702 gross, 42,355 net acres 100% WI, 83% avg. NRI $52 MM 2005 capex 18 wells, 6 recompletions 6 Mcfe/d net production (Feb. 2005) 94 mile gathering system Uinta Basin DRILLING SCHEDULE D 17 wells

E = Exploratory wells D = Development wells = Key information/results available 3D = 3D seismic survey SCALE 1 Township = 36 sq mi Key Well 14-1 Marsing (1975) 4,000' gas saturated Mesaverde section Lake Canyon Brundage Canyon Lake Canyon / Brundage Canyon Basin Centered Project 278,995 Gross / 200,566 Net Acres (Mar. 2005) Altamont/Bluebell Duchesne Structural Level of Natural Buttes Barrett Acreage Mesaverde Penetrations Oil Producers Pipelines Faults Temporarily Abandoned Planned 57 sq mi 3D Seismic Survey Shallow Green River locations Green River E 2 wells 2005 2006 BASIN Q1 Q2 Q3 Q4 Q1 Q2 AREA Mesaverde E 3D Uinta 3D E DRILLING SCHEDULE

World Class Structure Multiple Pay Horizons Multiple Drilling Inventories in Each Field Waltman Arch East-West Seismic Profile 15+ miles West East 15,000' Mesaverde 6000' uplift Lance Cody Frontier Muddy Tensleep Basement Fort Union THRUST WALTMAN ARCH Up Down Meeteetse Raderville

Waltman Arch Wind River Basin Cave Gulch Waltman Bullfrog Cooper Reservoir Wallace Creek Windjammer Pommard East West Stone Cabin Scale in Miles 0 6 Thrust Arch Waltman Barrett Acreage Structural Axes Thrust Faults Gas Productive Area Oil Productive Area WYOMING Wind River Basin Large contiguous acreage position with 375 miles of 3D Development Program $29 MM 2005 Capex (12 wells, 2 recompletes) 153,126 gross, 75,496 net acres 38% HBP/HBU 75-100% WI Exploratory Joint venture program 6 identified plays E = Exploratory wells D = Development wells = Key information/results available 12-well Dev. program D Development Waltman Arch 2005 2006 BASIN Q1 Q2 Q3 Q4 Q1 Q2 AREA Start 18-well Expl. program E DRILLING SCHEDULE Joint Venture

Madden 3+ Tcfe Frenchie Draw 100+ Bcfe EAST MADDEN 3-D Play Lance Basin - Centered Gas Owl Creek Thrust Fault Thrust Arch Waltman Area of New Ft. Union and Lance Production Hitchcock Draw 16,600' Test BBC Talon Unit BBC WI 44-64% Yates Mahoney Unit BBC WI 44-100% Yates Riverbank Unit BBC WI 44% TALON Testing Testing BBC WI 37.5% Wind River - Basin Centered Gas Project 262,060 Gross and 93,199 Net Acres Barrett Acreage Gas Well Faults E = Exploratory wells D = Development wells = Key information/results available East Madden Talon 2005 2006 BASIN Q1 Q2 Q3 Q4 Q1 Q2 AREA E 9 well program E DRILLING SCHEDULE Wind River WYOMING Wind River Basin Talon and East Madden

40 Bcfe Est. Proved Reserves, 201 Bcfe P3 Reserves (Dec. 31 2004) $20 MM 2005 Capex (250 Big George wells) 23 MMcfe/d Net Production (Feb. 2005) 47,290 Net Undeveloped Acres (Mar. 2005) MT WY Powder River Basin Barrett Acreage Gas Producing Area Cat Creek Amos Draw DeadHorse Willow Creek Porcupine Palmtree BIG GEORGE PLAY Union Outcrop Fort Gillette, WY Fort Outcrop Union SCALE 1 Township = 36 sq mi Tuit WYODAK PLAY Powder River Basin - Coal Bed Methane E = Exploratory wells D = Development wells = Key information/results available Powder River 2005 2006 BASIN Q1 Q2 Q3 Q4 Q1 Q2 AREA DRILLING SCHEDULE On-going 250 well program

Williston Basin - Horizontal Technology Play Predominantly Fee Lands Oil Component 31 Bcfe Est. Proved Reserves (Dec. 31, 2004) Development Program $9 MM 2005 Capex (6 wells, 1 re-entry) 7 MMcfe/d Net Production (Feb. 2005) 191,400 Gross / 120,855 Net / 113,403 Net Undeveloped Acres (Mar. 2005) Exploratory Joint Venture Program 7 wells Barrett Acreage Oil Field Gas Field SOUTH DAKOTA MONTANA Williston Basin Mapped Area NORTH DAKOTA Grand River Red River "B" Play Red River "B" Oil Saturation Area Cedar Creek Anticline Scale in Miles 0 30 Cedar Hills Field Bakken Trend Indian Hills Madison Play Target-Red Bank Madison Play Red Bank Extension Madison Play Mondak Bakken Play

Target/Red Bank/Red Bank Extension Williston Basin, Montana & North Dakota Scale: 640 ac = 1 Mile (with 40 ac grid) Target 85 -100% WI Red Bank Extension 65 -100% WI Red Bank 90 -100% WI M O N T A N A N. D A K O T A IP: 200 Bopd Horizontal Technology Play Multi-Pay Potential IP: 300 Bopd IP: 70 Bopd IP: 70 Bopd Total leasehold 78,284 gross, 61,858 net acres E = Exploratory wells D = Development wells = Key information/results available 2005 2006 Q1 Q2 Q3 Q4 Q1 Q2 D 4 wells Williston Target/Red Bank E 4 wells DRILLING SCHEDULE BASIN AREA Barrett Acreage Oil Well Barrett Operated Well Barrett 2005 Dev. Location Horizontal Well

E = Exploratory wells D = Development wells = Key information/results available Indian Hills Williston Basin, North Dakota Scale: 640 ac = 1 Mile (with 40 ac grid) Total leasehold 11,662 gross, 6,854 net acres 35 - 75% WI Drilling Horizontal Madison Potential IP: 125 Bopd 2005 2006 BASIN Q1 Q2 Q3 Q4 Q1 Q2 AREA Indian Hills D Williston E DRILLING SCHEDULE Barrett Acreage Oil Well Barrett Operated Well Horizontal Well

E = Exploratory wells D = Development wells = Key information/results available Mondak Bakken Play Williston Basin, Montana & North Dakota Bakken Trend M O N T A N A N. D A K O T A Nance Bakken Discovery 250 Bopd Barrett 6 locations 22% WI Barrett 9 locations 100% WI $825/ac. $910/ac. $710/ac. $580/ac. $750/ac. Burlington locations $1,792/ac. $310/ac. Scale: 640 ac = 1 Mile (with 40 ac grid) Total leasehold 9,563 gross, 6,086 net acres 2005 2006 BASIN Q1 Q2 Q3 Q4 Q1 Q2 AREA Mondak Williston DRILLING SCHEDULE E possible 6-8 wells Barrett Acreage Recent BLM Sale Oil Well Horizontal Well

Redwater Bakken Play Williston Basin, Montana Bakken Trend Scale: 640 ac = 1 Mile (with 40 ac grid) Barrett 95 - 100% WI 35 potential locations 10 million barrel target Barrett Exploratory Location Total leasehold 20,862 gross, 20,279 net acres E = Exploratory wells D = Development wells = Key information/results available 2005 2006 BASIN Q1 Q2 Q3 Q4 Q1 Q2 AREA Redwater E Williston DRILLING SCHEDULE Barrett Acreage Oil Well Horizontal Well

E = Exploratory wells D = Development wells = Key information/results available Grand River Williston Basin, North & South Dakota Scale: 640 ac = 1 Mile (with 40 ac grid) Total leasehold 22,998 gross, 17,397 net acres 75 - 100% WI Barrett Horizontal Exploratory Location N O R T H D A K O T A S O U T H D A K O T A Horizontal Red River "B" producer High potential Red River "B" zone Horizontal Exploration Trend 2005 2006 BASIN Q1 Q2 Q3 Q4 Q1 Q2 AREA Grand River E Williston DRILLING SCHEDULE Barrett Acreage Oil Well Red River B Show Well Horizontal Well

Exploration Fairway Tri-State, DJ Basin Barrett Acreage Oil Field Gas Field Scale in Miles 0 30 Beecher Island EUR: 130 Bcfe Niobrara Celia 2,613 MBbls Pennsylvanian Goodland EUR: 13 Bcfe Niobrara Bonny EUR: 79 Bcfe Niobrara Republican EUR: 87 Bcfe Niobrara Cahoj 8,878 MBbls Pennsylvanian 367,426 Gross and 173,011 Net Undeveloped Acres Predominantly Fee (Year-round Drilling) Excellent access to pipeline infrastructure Explore applying horizontal technology 226 miles 2D Proprietary & 755 mile licensed 2D 24 sq. miles 3D Seismic 530 miles 2D Seismic planned for 2005 90 sq. miles 3D follow-up (dependent on 2D results) WY CO KS NE DJ Basin Tri-State Project Cherry Creek EUR: 15 Bcfe Niobrara Goodland St. Francis 3D outline E = Exploratory wells D = Development wells = Key information/results available 2D or 3D = seismic survey 2005 2006 BASIN Q1 Q2 Q3 Q4 Q1 Q2 AREA Tri-State E 2 wells 2D DJ 2D 3D DRILLING SCHEDULE N E B R A S K A Burlington K A N S A S C O L O R A D O

Denver, CO Big Horn Basin Powder River Basin Green River Basin Uinta Basin Piceance Basin Paradox Basin Williston Basin DJ Basin Wind River Basin San Juan Basin Rocky Mountain Basin Centered Gas Basin Centered Gas Gas Prone Area Oil Prone Area

Basin Centered Gas Project Big Horn Basin 93,224 Net Undeveloped Acres Long-term Acreage Prolific Hydrocarbon System Multiple "Giant" Fields Large Un-drilled Region Targeting Basin Centered Gas WYOMING Big Horn Basin SCALE 1 Township = 36 sq mi Area of Basin Centered Gas Play E = Exploratory wells D = Development wells = Key information/results available 2D or 3D = seismic survey 2005 2006 BASIN Q1 Q2 Q3 Q4 Q1 Q2 AREA Big Horn 2D 2D DRILLING SCHEDULE E

Denver, CO Big Horn Basin Powder River Basin Green River Basin Uinta Basin Piceance Basin Paradox Basin Williston Basin DJ Basin Wind River Basin CBM Harding - - Putnam - - Nameless - - Mondak Bakken Cave Gulch Cooper Reservoir Wallace Creek Talon West Tavaputs Gibson Gulch Extensive Development Inventory Diversified portfolio - geographically and geologically 12 core producing/development areas 95 MMcfe/d net production (Feb. 2005) 292 Bcfe proved reserves at YE 2004 1.2 Tcfe P3 reserves 2,258 gross un-risked P3 drilling locations 7 year drilling inventory Large WI, range 38-100%, majority 94+% Gas Prone Area Oil Prone Area Development Project Hill Creek Cedar Camp Red Bank/Target Indian Hills

Significant Exploration Upside 24 exploration projects (^ 65 prospects) 70% unconventional Over 10 Tcfe unrisked potential Dominant lease position in high potential areas Approximately 800 sq. mi. 3-D seismic coverage Budgeted 16 exploration wells in 2005 Denver, CO CBM Wyodak, Big George Hook Unrisked Target Size 50-250 Bcfe (3 areas) 250-500 Bcfe (4 areas) Note: one area not shown for competitive reasons 500 Bcfe to Multi-Tcfe (8 areas) Note: one area not shown for competitive reasons Big Horn Basin Powder River Basin Green River Basin Uinta Basin Piceance Basin Paradox Basin Williston Basin DJ Basin Wind River Basin Waltman Arch 6 Projects Lake Canyon, Brundage Canyon Tavaputs Gibson Gulch Big Horn Tri-State Pine Ridge Yellow Jacket