April 2004 Update

14 Inverness Drive East, Suite H-236Englewood, CO 80112-5625www.gascoenergy.comPhone: 303-483-0044 • Fax: 303-483-0011

Mark EricksonPresident & CEO

Natural Gas Growth

OTCBB: GASE

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Forward-Looking Statements Certain statements set forth in this presentation relate to management’s future plans, objectives and

expectations. Such statements are forward looking within the meanings of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. All statements other than statements of historical facts included in this presentation, including, without limitation, statements regarding the Company’s future financial position, business strategy, budgets, projected costs and plans and objectives of management for future operations, are forward looking statements. In addition, forward- looking statements generally can be identified by the use of forward-looking terminology such as “may,” “will,” “expect,” “intend,” “project,” “estimate,” “anticipate,” “believe,” or “continue” or the negative thereof or similar terminology. Although any forward-looking statements contained in this presentation are to the knowledge or in the judgment of the officers and directors of the Company, believed to be reasonable, there can be no assurances that any of these expectations will prove correct or that any of the actions that are planned will be taken. Forward-looking statements involve known and unknown risks and uncertainties that may cause the Company’s actual performance and financial results in future periods to differ materially from any projection, estimate or forecasted result. Some of the key factors that may cause actual results to vary from those the Company expects include inherent uncertainties in interpreting engineering and reserve or production data; operating hazards; delays or cancellations of drilling operations because of weather and other natural and economic forces; fluctuations in oil and natural gas prices in response to changes in supply; competition from other companies with greater resources; environmental and other government regulations; defects in title to properties; increases in the Company’s cost of borrowing or inability or unavailability of capital resources to fund capital expenditures; and other risks described under “Risk Factors” in Part I, Item 1 of the Company’s latest Annual Report on Form 10-K filed with the Securities and Exchange Commission.

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Rocky Mountain Natural Gas Focus Predictable, low-risk reserve adds going forward Low geologic risk, statistical play Technology and completion-efficiency driven Robust internally generated, multi-pay prospect portfolio Control 274,019 gross acres; 141,435 net acres (3/26/04)

Production / Reserves (100% Utah) Current gross production (3/26/04) : 3.40 MMcfd Current net production (3/26/04) : 2.00 MMcfd Proved reserves (pro forma 12/31/03 for COP Acquisition) : 20.7 Bcfe

Financial / Capitalization Raised $59 MM in one debt and five equity tranches

• Recent $21.5 MM equity offering completed in two days in early Feb. 2004 Management and Director ownership 14.3% At 3/26/04 : cash $17.7 MM / debt $2.5 MM

Solid NAV Growth Platform

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Regional Gas Potential & % Restricted

*Source: US Geologic Survey & Potential Gas Committee / excludes CBM

21 Tcf

100% 31 Tcf

100%

346 Tcf

40%

43 Tcf

56%

#1 Uinta Basin – > than 30.7 Tcf*

#2 Green River Basin – 18.5 Tcf

Gasco Rocky Mountain Focus AreasUS Tight Sand Resource Estimates

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Corporate Strategy

Cause drilling to happen.

Increase production and proven reserves.

Increase the value of probable and possible reserves.

“Growth through the Bit”

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Reserve Value Recognition

* Pro forma reserves (12/31/03) run at a net Rocky Mountain Price of $5.89 Mcf/$29.69 Bbl after adjustments for energy content and transportation fees. Pro forma reserves include 3/04 COP acquisition @ 75% interest acquired. Assuming 3rd party exercises its right to acquire 25% of COP Acq.

Gasco’s Net Acreage

Acreage with Proven Reserves (Pro forma 12/31/03*)

99% Unproven

<1% Proven

Acreage Allocation

Proven Reserve Value $21.6 MMPro forma 12/31/03*

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Riverbend Wells are Building Blocks

1 PDP (unrisked) $ 3.0 MM 8 PUD (unrisked) $ 8.0 MM 16 Probable (risked 50%) $ 8.0 MM

Total* $19.0 MMPredictable &

Sustainable Growth

=

$2.00 MM well investment can create up to $19 MM in NAV

30-year reserve life provides predictable cash flow

*Assumes PV-10, Gasco type well 2.0 Bcf & $4.50 NYMEX 100% WI / 80% NRI

PROB

PROB

PROB

PROB

PROB PROB PROB PROB PROB

PROB PROB PROB PROB

PROB

PROB

PROB

PUD

PUD

PUD

PUD

PUD

PUD

PUD

PUD

PDP

Based on 40-acre spacing

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Senior Management TeamProven Gas Finders and Company Builders “Rocky Mountain Technical Experts”

Mark Erickson, President & CEO Co-founded Pennaco Energy

Michael Decker, EVP & COO Former VP of Exploitation, Prima Oil & Gas

King Grant, EVP & CFO Former SVP, Natural Resources Group, ING Barings

John Longwell, Operations Manager Former SVP of Operations, Prima Oil & Gas

Average 20 years oil and gas experience

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Focuses on lowering per-unit costs

Team-oriented, tailor-made D&C operations

Applying proven, tight-sand technologies

Steepens the learning curve

Service Parties Agreement

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PowerSTIM (SLB) Team-oriented well optimization service from spud through production Focus on reducing completion time, driving down per-unit costs and

maximizing economies of scale Advanced, multi-application completion technologies

CoilFRAC (SLB); Induced Stress Diversion (SLB); FAS DRILL (HAL)

Technology and Rockies Expertise

FAS DRILL

Frac PlugCoilFRAC

Basin-specific Engineering and Technology Maximizes Production

PowerSTIM

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Agreement Components

Up to 50 wells in five, 10-well bundles ($100 MM) Bundle election by parties 50 wells = less than 5% of Gasco net Riverbend locations

Gasco can fund up to 20% of each of first three bundles and up to 30% of remaining bundles

Non-recourse payments out of production Payments proportionate to service-dollars risked Service provided at market rate Payments only from the PDP location

Gasco can continue to develop its acreage independent of this agreement

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GREATER GREENRIVER BASIN

UINTA BASIN

DENVER(GASE HQ)

UT CO

WY

Core Operating Areas

Uinta Basin, Utah Wasatch, Mesaverde and Blackhawk

formations Active Players:

Bill Barrett Corp., Dominion Resources (D), EOG Resources (EOG), Inland, Questar (STR), Samson Resources, St. Mary Land (SM), Stone Energy (SGY), Westport (WRC)

Green River Basin, Wyoming Fort Union, Lance, Mesaverde, Ericson

and Rock Springs formations Active Players:

BP Amoco (BP), EnCana (ECA), EOG Resources (EOG), Shell (RD), Stone Energy (SGY), Ultra Petroleum (UPL), Western Gas Resources (WGR), Williams (WMB)

SALT LAKE CITY

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Acreage (Federal 80%, State 19%, Fee 1%) 119,259 gross (59,858 net) acres, with 19,324 gross

(12,297 net) acres remaining to be earned or assigned at 3/26/04.

Potential gross locations: 3,000 Potential net locations: 1,450 Potential operated locations: 2,000 Gasco unrisked net resource potential: 1-2 TCF

Operations 11 gross wells Production (3/26/04)

Gross 3.40 MMcfd Net 2.00 MMcfd

Proved Reserves: 12/31/03 (NSAI) 14.2 Bcfe3/04 COP Acq.* 6.5 Bcfe

20.7 Bcfe=============

* Pro forma reserves include 3/04 COP acquisition @ 75% interest acquired. Assuming 3rd party exercises its right to acquire 25% of COP Acq.

Riverbend Project - Uinta Basin, Utah“A Legacy Asset”

ID

WY

RiverbendProject

UT CO

1.0+ Tcfe Cum.

Production

Natural Buttes

PUD 80%

PDP 20%

Reserve Breakdown

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Key Pipelines

Leases

Wells &

Locations

Significant PotentialActivity

Riverbend ProjectUinta Basin, Utah

155 Industry Wells Drilled2 P&A

47 Months as of 10/22/2003

Gasco Riverbend Wells

Mapped area approx. 50 miles X 30 miles

GASCORiverbend Wells

6 miles

GASCOGate Canyon Area

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Riverbend ProjectCompetitive Landscape

Bill Barrett Corp. Dominion / EOG / Samson

Dominion / Questar

Stone / Inland / Yates

Samson

EOG

Westport Resources (Kerr-

McGee?)St. Mary Land

Gasco Leases

Gasco Riverbend Wells

6 miles

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Implementation

Accelerate drilling program.

Continually improve drilling and completion efficiency.

Maintain high working interest.

Operate whenever possible.

Riverbend Project

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Riverbend Cross Section

Wasatch(7000’ - 9000’)

Upper Mesaverde(9000’ - 11,000’)

Lower Mesaverde(11,000’ - 12,500’) 0.75 to 1.5 Bcf Estimated

0.5 to 1.0 Bcf Estimated

0.25 to 1.0 Bcf Estimated

Riverbend Type Well*

D&C $2.0 - $2.5 MM 1.25 to 5.50 Bcf 30 Days to TD @ 12,000’Over-pressured Gas

8250 PSI

3450 PSI

5500 PSIOver-pressured Gas

Normal-pressured Gas

Riverbend Project

Repeatability Manufacturing model Low geologic risk Statistical play

*Hypothetical case; actual well

results may vary from this diagram.

Blackhawk(12,500’ - 14,000’) 1.0 to 2.0 Bcf Estimated

9275 PSIOver-pressured Gas

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Mesaverde / Wasatch Type Well

Riverbend Project, Uinta Basin, Utah"Wasatch & Mesaverde" Type Well

1,000

10,000

100,000

0 12 24 36 48 60

Months

Gro

ss M

cf P

er M

on

th

Annual Decline

Year %

1 50-60

2 25-30

3 15

4 12

5 10

6 8

7- 30 6

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ID

WY

UT CO

Jonah FieldMoxa Arch

Pinedale Anticline

Muddy Creek Project

Wyoming Projects Green River Basin, WY

Acreage (Federal 90%, State 9%, Fee 1%) 112,582 gross (62,614 net) acres, with 22,854

gross (6,667 net) acres remaining to be earned or assigned at 3/26/04

Total potential locations: 3,000+ Operated locations: 500+ ( > 50% Avg. WI) Gasco unrisked net resource potential : 0.5 -1.0

TCF

Operations 200 miles 2-D seismic acquired. 100 miles 3-D seismic acquired. 6 Burlington wells drilled, completed and

flowing. 3 Gasco wells drilled, 1 completed waiting on

pipeline. 2 Potential Discoveries (Grindstone & Muddy

Creek Projects).

Grindstone ProjectMerna

Field

LaBarge Platform

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Takeaway Capacity

GREATER GREENRIVER BASIN

UINTA BASIN

Northwest 475

CIG 355

Kern 1,770

TransColorado 850

WNG 180

KMI (Pony Express) 410

Trailblazer 850

4,540

Ruby (EPG) 200

Advantage (KMI) 320

Bison NBP) 300

Cheyenne Plains 2005 540

1,360

PipelineTakeaway

MMcf/d

UT

IDWY

MTND

SD

CO

NE

NMAZ

Expansion

EAST

WEST

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Gasco Natural Gas Price

Netback*

Henry Hub (MMBtu): $ 5.76

Basis differential:

Wyoming Pool (MMBtu):

$

$

(0.70)

5.16

Gathering, marketing & transportation: $ (0.30)

Net wellhead price (MMBtu): $ 4.86

Heat content adjustment: 1.125

Wellhead netback (Mcf): $ 5.47

Shrink and fuel loss: 2.5%

*www.enernetenergy.com – reported 4/8/04 for close on 4/7/04

All Gasco production is currently unhedged

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Share Related at 3/26/04

Common shares outstanding

Preferred series (converted)

Convertible Debentures

Total options

Fully diluted shares

Capital Summary

Shares 000s

6,910

4,151

% Fully Diluted Shares

9.0%

5.4%

14.3%#

Shares 000s

63,364

3,947

4,167

5,637

77,115

**Management options exercise price from $1.00 to 3.15 (Avg. $1.69); All options exercise price from $1.00 to $3.70 (Avg. $1.84).

Management Ownership

Common Stock*

Options**

*Assumes management’s Preferred position is converted to Common # Does not foot due to rounding

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Positioned for Growth

Capital in place

Large inventory of predictable, repeatable, low-risk

reserve adds

Gasco’s Net Acreage

Acreage with Proven Reserves

99% Unproven

<1% Proven

Acreage Allocation

Low geologic risk;

statistical play

Leading industry partners

contributing technology

and risked services