35-CERT

UNITED STATES OF AMERICA
           Before the
SECURITIES AND EXCHANGE COMMISSION

In the Matter of
                                            
NATIONAL FUEL GAS COMPANY
HORIZON ENERGY DEVELOPMENT, INC.
HORIZON ENERGY HOLDINGS, INC.
and its subsidiaries

File No. 70-9959
(Public Utility Holding Company Act of 1935)
THIRTEENTH
CERTIFICATE
PURSUANT TO
RULE 24

        THIS IS TO CERTIFY, pursuant to Rule 24, that certain transactions proposed by National Fuel Gas Company (“National”), its subsidiary, Horizon Energy Development, Inc. (“Horizon”), Horizon’s subsidiary, Horizon Energy Holdings, Inc. (“Holdings”), and Holding’s subsidiaries (“Intermediate Subsidiaries”), in their Application-Declaration on Form U-1, as amended (File No. 70-9959), have been carried out in accordance with the terms and conditions of said Application-Declaration and the Order (HCAR No. 35-27487, dated December 31, 2001) of the Securities and Exchange Commission (the “Commission”) with respect thereto, and that the following information for the quarter ended March 31, 2005 is herein provided:

1) A general description of the Development Activities of Horizon or any Intermediate Subsidiary during the quarter and of any exempt wholesale generator or foreign utility company in which National has acquired, directly or indirectly, an ownership interest during the quarter:

Horizon and Intermediate Subsidiaries engaged, directly or indirectly, in one or more of the following Development Activities during the quarter: preliminary engineering; preparation of bid proposals; application for required permits and/or regulatory approvals; negotiation and execution of contractual commitments with power purchasers and other project contractors; discussion of financing opportunities with lenders and other third-party investors; and such other preliminary activities as may be required to develop, construct, and operate electric generation plants.

During the quarter, Horizon, through Intermediate Subsidiaries, continued to hold ownership interests in Sofia Energy EAD and Montenero Energia s.r.l. Each of these entities is pursuing a power generation project — Sofia Energy EAD in and around the city of Sofia, Bulgaria, and Montenero Energia s.r.l in the Molise region of Italy near the town of Montenero di Bisaccia.

2) Information on Project Services (administrative, operating, technical and management services) performed during the quarter:

Company Providing Service	Company Receiving Service	Type of Service	Total Charges*	At Cost or Fair Market Value
Horizon	Horizon Energy Development, s.r.o.	Technical and management services	$50,000 1	Fair market value
Horizon Energy Development, s.r.o.	Horizon	Administrative services	$36,800 1	Fair market value
Horizon Energy Development, s.r.o.	United Energy, a.s.	Administrative and operating services	$258,621	Fair market value
United Energy, a.s.	Teplarna Liberec, a.s.	Administrative and management services	$133,784	Fair market value

*	Amounts are shown in US$. Original billings may be calculated in Czech Korunas. For the quarter ended March 31, 2005, the average spot exchange rate was CZK22.91/US$1.
1	Represents estimated amount accrued during quarter. Payments are generally made at the end of fiscal year and calendar year.

3)     Information regarding new Intermediate Subsidiaries:

        No new Intermediate Subsidiaries were established or acquired during the quarter.

4)     Amount of any Guarantee issued by Horizon or any Intermediate Subsidiary that is not exempt under Rule 45(b) or Rule 52:

        Neither Horizon nor any Intermediate Subsidiary issued any such Guarantee during the quarter.

5)     Horizon financial statements:

Horizon’s balance sheet at March 31, 2005 is attached as Exhibit 1, and Horizon’s income statement for the quarter ended March 31, 2005 is attached as Exhibit 2.

        IN WITNESS WHEREOF, the undersigned companies have caused this Certificate to be executed as of this 18th day of May, 2005.

NATIONAL FUEL GAS COMPANY

By: /s/   R. J. Tanski
       R. J. Tanski
       Treasurer

HORIZON ENERGY DEVELOPMENT, INC.

By: /s/   R. J. Tanski
       R. J. Tanski
       Secretary and Treasurer

HORIZON ENERGY HOLDINGS, INC.

By: /s/  R. J. Tanski
       R. J. Tanski
       Secretary and Treasurer

EX-99

Exhibit 1

HORIZON ENERGY DEVELOPMENT, INC.
BALANCE SHEET
(Unaudited)

	At March 31, 2005
ASSETS
Property Plant & Equipment
Property Plant & Equipment	$	448,705,575
Accumulated D, D & A		(205,141,547	)
Net Property, Plant & Equipment		243,564,028
Current Assets:
Cash and Temporary Cash Investments		55,902,220
Notes Receivable-Intercompany		600,000
Receivables - Net		10,900,277
Accounts Receivable-Intercompany		228,885
Unbilled Utility Revenue		0
Materials/Supplies - Average Cost		4,489,667
Prepayments		673,003
Current Assets		72,794,052
Other Assets		354,318
Total Assets	$	316,712,398
CAPITALIZATION & LIABILITIES
Capitalization:
Capital Stock of Subsidiaries	$	4,750
Paid in Capital		38,245,591
Earnings Reinvested in Business		(7,898,767	)
Accumulated Other Comprehensive Income		52,946,784
Total Common Stock Equity		83,298,358
Long-Term Debt Net of Current Portion		2,696,407
Notes Payable - Intercompany - Long Term		89,770,000
Total Capitalization		175,764,765
Minority Interest in Foreign Subsidiaries		43,882,862
Liabilities:
Notes Payable - Intercompany		39,400,000
Long Term Debt Due Current		5,392,812
Accounts Payable - Other		15,150,128
Accounts Payable - Intercompany		3,491,602
Other Accruals & Current Liabilities		9,136,415
Total Current Liabilities		72,570,957
Deferred Credits:
Accumulated Deferred Income Tax		21,030,683
Other Deferred Credit		3,463,131
Total Deferred Credits		24,493,814
Total Capitalization & Liabilities	$	316,712,398

EX-99

Exhibit 2

HORIZON ENERGY DEVELOPMENT, INC.
INCOME STATEMENT
(Unaudited)

	Three Months Ended March 31, 2005
Operating Revenue:
Operating Revenue	$	55,486,829
Operating Expenses:
Fuel Used in Heat and Electric Generation		26,191,625
Operation and Maintenance Expenses		6,787,068
Property, Franchise & Other Taxes		870,307
Depreciation, Depletion & Amortization		4,717,475
Operating Expenses		38,566,475
Operating Income		16,920,354
Other Income		335,011
Interest Charges		1,849,378
Net Income Before Income Taxes		15,405,987
Income Taxes - Current		7,037,573
Income Taxes - Deferred		804,565
		7,842,138
Minority Interest in Foreign Subsidiaries		(2,405,487	)
Net Income	$	5,158,362