Exhibit 99.1

Howard Weil 35^th Annual Energy Conference

Steven F. Leer Chairman and CEO

Arch Coal, Inc.

April 4, 2007 New Orleans, LA

Forward-looking information

This presentation contains “forward-looking statements” –that is, statements related to future, not past, events. In this context, forward-looking statements often address our expected future business and financial performance, and often contain words such as “expects,”“anticipates,” “intends,”“plans,” “believes,”“seeks,”or “will.” Forward-looking statements by their nature address matters that are, to different degrees, uncertain. For us, particular uncertainties arise from changes in the demand for our coal by the domestic electric generation industry; from legislation and regulations relating to the Clean Air Act and other environmental initiatives; from operational, geological, permit, labor and weather-related factors; from fluctuations in the amount of cash we generate from operations; from future integration of acquired businesses; and from numerous other matters of national, regional and global scale, including those of a political, economic, business, competitive or regulatory nature. These uncertainties may cause our actual future results to be materially different than those expressed in our forward-looking statements. We do not undertake to update our forward-looking statements, whether as a result of new information, future events or otherwise, except as may be required by law. For a description of some of the risks and uncertainties that may affect our future results, you should see the risk factors described from time to time in the reports we file with the Securities and Exchange Commission.

This presentation includes certain non-GAAP financial measures, including Adjusted EBITDA. These non-GAAP financial measures are not measures of financial performance in accordance with generally accepted accounting principles and may exclude items that are significant in understanding and assessing our financial results. Therefore, these measures should not be considered in isolation or as an alternative to net income from operations, cash flows from operations, earnings per fully-diluted share or other measures of profitability, liquidity or performance under generally accepted accounting principles. You should be aware that

our presentation of these measures may not be comparable to similarly-titled measures used by other companies. A reconciliation of these financial measures to the most comparable measures presented in accordance with generally accepted accounting principles has been included at the end of this presentation.

Slide 2

U.S. coal markets weakened in 2006, but may be on the rebound

Factors causing demand decline

2006 (in millions of tons) ` Mild winter; mild summer (East)

+26

` Near-record nuclear availability Supply +26 ` Strong hydro year

+8

Low gas prices allowed coal -10 Demand            stockpile conservation efforts

` Led to generator stockpile increase of an estimated 35 million tons

Correction may be near

` Stronger gas prices ` Seaborne coal markets strengthening

` Return of normal weather ` Met market – tugging at steam

` Electric generation up 5% YTD ` Long-term supply pressures in East
` Coal production flat YTD ` New plants on horizon

` Renewed CAPP permitting issues Slide 3 Source: ACI and NMA

EIA projects U.S. coal use and market share to increase over next 25 years

Market Share by Fuel Type U.S. Fuel Prices

(in billion kWh) ($/mm BTU, at 3/30/07)

57% Coal 49% 15%

Nuclear $12.04 19% $9.89 17% Natural Gas 20% 5% Hydro 7% 4% $0.52 Renewable 3% PRB 8800 Nat. Gas Crude Oil 2%

Crude Oil FOB mine (2008) wellhead (Jan. 2008) 2% 2006 2030

Slide 4 Source: EIA, Platts and NYMEX

Increased utilization at existing coal-fueled generation plants can expand demand Just filling in troughs could equate to an incremental 100+ million tons of coal demand ⁽¹⁾ Peaking Oil/Gas Nat Gas (cc) Inter- mediate            Coal (cycling) Coal (baseload) Baseload Nuclear Hydro Summer            Spring            Winter            Fall ⁽¹⁾ Assumes 80% peak utilization vs. 73% average utilization Assumes a 14.8-million-ton increase for every 1% increase in utilization Slide 5 Source: ACI (for illustrative purposes only)

Construction is now underway on more than 11 GW of new coal-fueled capacity

WPS Weston #4 (Wisc.) Cleco Rodemacher #3 (La.) OPP Nebraska City #2 (Neb.) 500 MW / June 2008 600 MW / June 2008 663 MW / May 2009

.S. Power Boulder Valley (Nev.) MidAmer. Council Bluffs (Iowa) Elm Road Generating (Wis.) 200 MW / Jan. 2010 790 MW / May 2007 600 MW / July 2009

Slide 6 Source: ACI

Powder River Basin is expected to supply majority of new coal-fueled capacity

Under Construction            Advanced Development            Early Development 11.0 10.5 20.7 GW            GWGW PRB            Illinois            PRB            Illinois            Other            PRB            Illinois             Other CAPP            NAPP            NAPP            WBIT            Lignite            NAPP            Lignite &nbs p;          CAPP

Total coal demand of            Total coal demand of            Total coal demand of 40.8 million tons 36.1 million tons 74.3 million tons            Powder River Basin Powder River Basin            Powder River Basin expected to capture expected to capture expected to capture 33.8 million tons 16.9 million tons 26.3 million tons

New coal-fueled generating capacity announcements total over 90 GW.

Slide 7 Source: Platts and ACI estimates

We expect railroads to facilitate future growth in moving Western coals eastward

Donkey Creek Jct.

Railroads have facilitated

3rd Main

doubling of production in 39 Miles Caballo Mine            Powder River Basin since 1992 (North End of Joint Line)

Coal

Creek

New expansion projects are Black Thunder underway 3rd Main            Reno Jct (North Load out) added in Black Thunder ` 39 miles of triple track to be 2006 (South Load out) added north of Reno Junction West Nacco Jct

` 15 miles of quadruple track to Converse Jct 4th Main be added at Logan Hill @ Logan ` 15 Miles 42 miles of quadruple track Bill planned for Shawnee Junction These expansions are projected 4th Main            Walker 42 Miles to increase capacity by at least 75 million tons            Shawnee Jct

(South

End of Joint Line)

Slide 8 Source: ACI

Over the long-term, clean-coal technologies can create new markets for coal

A plug-in hybrid is one            Coal can be converted            Gasification can reduce entry for coal into the into ultra-low-sulfur emissions & transform transportation market diesel fuel coal into pipeline-quality natural gas

` Likely to create ` At current oil prices, significant coal-to-liquids ` IGCC & CCS should off-peak demand facilities appear enable coal to for electricity economically prosper in a carbon feasible constrained world

Public policy initiatives aimed at domestic energy security are leading to energy legislation and financial incentives for clean-coal-technology development.

Slide 9 Source: ACI

^{Debate on potential future CO}2 ^regulation
is focused on energy security and climate

Cannot reduce dependence on foreign oil without increased coal use

` Can advance clean-coal technology investment

Progress on carbon capture and storage (CCS) is accelerating

` ^{Stabilizing CO}2 ^{concentrations without CCS is virtually impossible}

` Recent announcement by AEP shows real progress on CCS

IGCC plants are now gaining traction

` Technology providers eager to establish the industry standard

Most realistic way to de-carbonize automotive fleet is to electrify (employing centralized CCS)

` Plug-in hybrids increasingly viewed as key part of solution

` Off-peak power demand will most benefit lowest cost fuels

Coal will remain a vital part of America’s –and the developing world’s – energy future

U.S. Energy Reserves Cumulative 4-Yr Percent Change (in trillion Btu) in Global Energy Consumption

(2001-2005, in millions toe)

Coal (95%) Coal 23.0% Coal (50%) Hydro 12.1%

NatGas

11.7%

Oil 7.9%

Nuke 4.4% Oil (2%) Natural Gas (3%)

China & India Rest of World

Slide 11 Source: EIA, Platts and BP Statistical Review of World Energy 2006

Arch Coal Overview

One of the largest U.S. coal producers

Headquartered in St. Louis, MO, with large, modern mining operations and strategic reserves spread across the U.S.

Core business is providing U.S. power generators with clean-burning, low-sulfur coal for electric generation

` Supplies roughly 11% of U.S. coal needs
` Provides source fuel for roughly 6% of U.S. electricity

Industry leader in mine safety, productivity and land reclamation

Slide 12 Source: ACI

Arch’s long-term success hinges on three crucial areas of performance Operating the world’s safest coal mines Acting as highly responsible stewards of the land and good corporate citizens Delivering superior shareholder value ` Achieving industry-leading rates of productivity ` Implementing continuous improvements and cost control initiatives ` Serving the growing needs of our utility and industrial customers Slide 13 Source: ACI

Arch has the cleanest balance sheet among major U.S. coal producers

Legacy Liabilities of Largest U.S. Coal Companies 12/31/06 (in millions) Pension Reclamation $3,357 Postretirement Medical Workers’ Comp

$2,267 $771 $397 $337 Competitor #1 Competitor #2 Competitor #3 Competitor #4 Arch Coal

Slide 14 Source: SEC filings compiled by ACI

Arch’s national scope of operations includes presence in four major U.S. coal basins

Powder River Basin

Illinois Basin

1. Coal Creek
2. Black Thunder

12 ¹2 4 Knight Hawk 2¹ 3 3 ⁴5 Centra

l Appalachia

1. Mountain Laurel

2. Co

al-Mac

Western Bituminous 3. Mingo Logan

4. Cumberland River

1. Skyline 5. Lone Mountain 2. Dugout 3. Sufco 4. West Elk

Reserve base of 2.9 billion tons (over 85% low-sulfur coal) Leading operating position in all three major low-sulfur basins            Equity interest in an Illinois Basin producer, Knight Hawk

Slide 15 Source: ACI

Arch is expanding coal markets through investment in coal-conversion technologies

Medicine Bow Mine End Products

DKRW            ultra-clean

11,000 bpd diesel fuel CTL Facility*

Wyoming

^gasificationtechnology            chemical Arch as mine operator feedstock ^{FT liquefaction} technology

^CO2

SNC-Lavalin to provide EPC services

enhanced oil recovery

Arch owns a 25% stake in DKRW Advanced Fuels

Long-term contract in place with Sinclair Oil Corporation to sell ultra-low-sulfur diesel fuel from planned CTL facility

Arch’s 2006 operating results demonstrated significant progress

Earnings per share Adjusted EBITDA

(per diluted share basis) (in millions) $1.80 $545 $290 $0.17 2005 2006 2005 2006

Achieved rising price realization per ton in all regions due to the roll-off of lower-priced contracts

Expanded operating margin per ton in all regions due to better price realization and cost control initiatives

Note: Reconciliation appears on last page of handout, may not tie due to rounding

Slide 17 Source: ACI

Arch plans to reduce production levels and contain costs in weak market cycle

Guidance

Reduce production targets (charts in millions) ` Preserve value of reserves for 2006 $502 future when demand rebounds 2007E

$260

Lower capital spending 127 133

` Align spending with market demand and reduced Volume midpoint* Capex midpoint**

production levels

` Focus on cost control            Unpriced tons at 12/31/06

Maintain upside exposure 110 — 120 ` Unpriced position translates 75 — 85 into more upside potential when market rebounds

` Creates long-term value for 11 — 16 shareholders

2007 2008 2009

*Volume excludes pass-through tons associated with Magnum transaction

Slide 18 **Capex excludes reserve additions Source: ACI

Arch’s future strategic growth possibilities are exciting

Invest in core businesses to enhance profit growth and return on capital as well as evaluate opportunities to further upgrade and expand reserve base            Consider acquisitions or investments that strategically fit and create shareholder value            Expand market for coal through Btu conversion technologies that provide significant upside

Slide 19 Source: ACI

Reconciliation to Non-GAAP Measures (Adjusted EBITDA)

Adjusted EBITDA:

Adjusted EBITDA is defined as net income before the effect of net interest expense; income taxes; our depreciation, depletion and amortization; expenses resulting from early extinguishment of debt; and other non-operating expenses.

Adjusted EBITDA is not a measure of financial performance in accordance with generally accepted accounting            principles, and items excluded to calculate Adjusted EBITDA are significant in understanding and assessing our financial            condition. Therefore, Adjusted EBITDA should not be considered in isolation nor as an alternative to net income, income            from operations, cash flows from operations or as a measure of our profitability, liquidity or performance under generally            accepted accounting principles. We believe that Adjusted EBITDA presents a useful measure of our ability to service and            incur debt based on ongoing operations. Furthermore, analogous measures are used by industry analysts to evaluate            operating performance. Investors should be aware that our presentation of Adjusted EBITDA may not be comparable to            similarly titled measures used by other companies. The table below shows how we calculate Adjusted EBITDA.

Year Ended December 31, 2006 2005 (Unaudited) Net income $ 260,931 $ 38,123 Income tax (benefit) expense 7,650 (34,650) Interest expense, net 60,639 63,120 Depreciation, depletion and amortization 208,354 212,301 Expenses from early debt extinguishment and other non-operating 7,447 11,264

Adjusted EBITDA $545,021$290,158 Slide 20 Source: ACI