Exhibit 99.1

Press Release August 5, 2011

HollyFrontier Corporation Reports Record Second Quarter 2011 Results

Dallas, Texas, August 5, 2011 — HollyFrontier Corporation (NYSE-HFC) (“HollyFrontier” or the “Company”) today reported record quarterly net income attributable to HollyFrontier stockholders of $192.2 million or $3.58 per diluted share for the quarter ended June 30, 2011, compared to $66.2 million or $1.24 per diluted share for the quarter ended June 30, 2010. For the six months ended June 30, 2011, net income attributable to HollyFrontier stockholders totaled $276.9 million or $5.16 per diluted share compared to $38.1 million or $0.71 per diluted share for the six months ended June 30, 2010.

For the most recent quarter, income increased by $126.1 million, or 191% compared to the same period of 2010. This increase in the most recent quarter was due principally to the effects of significantly higher refinery gross margins largely attributable to the considerable price differences between WTI crude oil and coastal crude oils like Brent and LLS. Substantially all of the crude oil run by HollyFrontier is priced at WTI or less. Overall refinery gross margins were $21.42 per produced barrel in the most recent quarter, a 95% increase compared to $11.01 for the same period last year. Production levels averaged 232,050 barrels per day (“BPD”) for the current year’s second quarter.

“We are extremely pleased with our second quarter results, reflecting the most profitable quarter in our history,” said Matthew Clifton, Executive Chairman of HollyFrontier. “Significant year-over-year margin improvements at each of our refineries, contributed to a 126% increase in EBITDA levels to $351 million for the three months ended June 30, 2011, compared to $155 million for the same period of 2010. Both our Tulsa and Navajo refineries earned approximately $140 million in EBITDA during the quarter. Our processing of lower priced WTI related crudes combined with strong transportation fuel cracks at all of our refineries helped fuel these improved results. Additionally, our Tulsa refinery benefited from attractive lube margins.

“Overall refinery production levels improved through the quarter as we rebounded from operational issues earlier in the year. For the month of June 2011, our total production was over 250,000 BPD and we have continued near such levels into the third quarter. We are on schedule for completion of the interconnect pipeline project at our Tulsa refinery later this summer. Upon completion, we expect the pipelines to lower operating expenses and enhance the earnings potential of our Tulsa refinery,” Clifton said.

HollyFrontier’s Chief Executive Officer and President, Michael Jennings, commented, “We completed our merger on July 1, 2011 forming the new HollyFrontier Corporation. Our integration of the two companies is moving along well and we are now starting to realize cost savings opportunities and operational synergies. The combination has strengthened our strategic position by diversifying revenue streams, expanding infrastructure and increasing asset scale.

We began the third quarter as a combined company with over $1.3 billion in cash and marketable securities and a new $1 billion revolving credit facility, making our financial condition one of the strongest among our independent refining peers.”

Sales and other revenues for the second quarter of 2011 were $2,967.1 million, a 38% increase compared to the three months ended June 30, 2010. This increase was due primarily to the effects of a 39% year-over-year increase in second quarter refined product sales prices. Cost of products sold was $2,447.1 million, a 32% increase compared to the second quarter of 2010 due mainly to higher crude oil acquisition costs.

Legacy Frontier Oil Corporation Second Quarter 2011 Results

For the quarter ended June 30, 2011, the legacy Frontier Oil Corporation (“Frontier”) business operations also generated strong quarterly results with net income of $167.1 million, or $1.57 per diluted share, compared to $66.1 million, or $0.63 per diluted share for the second quarter of 2010. EBITDA for the second quarter of 2011 was $296.2 million compared to $141.9 million for the same period last year. The legacy Frontier results of operations for the three and six months ended June 30, 2011 and 2010 are not included in the HFC results for the three and six month periods and will be made available in a HollyFrontier Form 8-K that will be filed with the SEC on August 8, 2011.

The Company has scheduled a webcast conference call for today, August 5, 2011, at 10:00 AM Eastern Time to discuss financial results. This webcast may be accessed at: http://www.videonewswire.com/event.asp?id=81267.

An audio archive of this webcast will be available using the above noted link through August 18, 2011.

HollyFrontier Corporation, headquartered in Dallas, Texas, is an independent petroleum refiner and marketer that produces high value light products such as gasoline, diesel fuel, jet fuel and other specialty products. HollyFrontier operates through its subsidiaries a 100,000 barrels per stream day (“bpsd”) refinery located in Artesia, New Mexico, a 125,000 bpsd refinery in Tulsa, Oklahoma, a 31,000 bpsd refinery in Woods Cross, Utah, a 135,000 bpsd refinery located in El Dorado, Kansas, and a 52,000 bpsd refinery located in Cheyenne, Wyoming. HollyFrontier markets its refined products principally in the Southwest U.S., the Rocky Mountains extending into the Pacific Northwest and in other neighboring Plains states. A subsidiary of HollyFrontier also owns a 34% interest (including the general partner interest) in Holly Energy Partners, L.P.

The following is a “safe harbor” statement under the Private Securities Litigation Reform Act of 1995: The statements in this press release relating to matters that are not historical facts are “forward-looking statements” based on management’s beliefs and assumptions using currently available information and expectations as of the date hereof, are not guarantees of future performance and involve certain risks and uncertainties, including those contained in our filings with the Securities and Exchange Commission. Although we believe that the expectations reflected in these forward-looking statements are reasonable, we cannot assure you that our expectations will prove correct. Therefore, actual outcomes and results could materially differ

from what is expressed, implied or forecast in such statements. Any differences could be caused by a number of factors, including, but not limited to, risks and uncertainties with respect to the actions of actual or potential competitive suppliers of refined petroleum products in the Company’s markets, the demand for and supply of crude oil and refined products, the spread between market prices for refined products and market prices for crude oil, the possibility of constraints on the transportation of refined products, the possibility of inefficiencies, curtailments or shutdowns in refinery operations or pipelines, effects of governmental and environmental regulations and policies, the availability and cost of financing to the Company, the effectiveness of the Company’s capital investments and marketing strategies, the Company’s efficiency in carrying out construction projects, the ability of the Company to acquire refined product operations or pipeline and terminal operations on acceptable terms and to integrate any future acquired operations, the possibility of terrorist attacks and the consequences of any such attacks, general economic conditions, our ability to successfully integrate the operations of Holly’s and Frontier’s businesses and to realize fully or at all the anticipated benefits of our “merger of equals” with Frontier, operational and legal risks and uncertainties detailed from time to time in the Company’s Securities and Exchange Commission filings. The forward-looking statements speak only as of the date made and, other than as required by law, we undertake no obligation to publicly update or revise any forward-looking statements, whether as a result of new information, future events or otherwise.

RESULTS OF OPERATIONS

Financial Data (all information in this release is unaudited)

		Three Months Ended
		June 30,								Change from 2010
		2011				2010				Change				Percent
		(In thousands, except per share data)
Sales and other revenues		$	2,967,133			$	2,145,860			$	821,273				38.3	%
Operating costs and expenses:
Cost of products sold (exclusive of depreciation and amortization)			2,447,095				1,848,212				598,883				32.4
Operating expenses (exclusive of depreciation and amortization)			139,345				120,831				18,514				15.3
General and administrative expenses (exclusive of depreciation and amortization)			18,682				15,829				2,853				18.0
Depreciation and amortization			31,832				28,824				3,008				10.4
Total operating costs and expenses			2,636,954				2,013,696				623,258				31.0
Income from operations			330,179				132,164				198,015				149.8
Other income (expense):
Equity in earnings of SLC Pipeline			467				544				(77	)			(14.2	)
Interest income			657				635				22				3.5
Interest expense			(15,193	)			(21,023	)			5,830				(27.7	)
Merger transaction costs			(2,316	)			—				(2,316	)			—
			(16,385	)			(19,844	)			3,459				(17.4	)
Income before income taxes			313,794				112,320				201,474				179.4
Income tax provision			111,961				39,654				72,307				182.3
Net income			201,833				72,666				129,167				177.8
Less net income attributable to noncontrolling interest			9,598				6,504				3,094				47.6
Net income attributable to HollyFrontier stockholders		$	192,235			$	66,162			$	126,073				190.6	%
Earnings per share attributable to HollyFrontier stockholders:
Basic		$	3.60			$	1.24			$	2.36				190.3	%
Diluted		$	3.58			$	1.24			$	2.34				188.7	%
Cash dividends declared per common share		$	0.15			$	0.15			$	—				—	%
Average number of common shares outstanding:
Basic			53,365				53,206				159				0.3	%
Diluted			53,670				53,408				262				0.5	%
EBITDA		$	350,564			$	155,028			$	195,536				126.1	%

		Six Months Ended
		June 30,								Change from 2010
		2011				2010				Change				Percent
		(In thousands, except per share data)
Sales and other revenues		$	5,293,718			$	4,020,150			$	1,273,568				31.7	%
Operating costs and expenses:
Cost of products sold (exclusive of depreciation and amortization)			4,431,712				3,572,076				859,636				24.1
Operating expenses (exclusive of depreciation and amortization)			274,088				248,375				25,713				10.4
General and administrative expenses (exclusive of depreciation and amortization)			35,500				33,698				1,802				5.3
Depreciation and amortization			63,140				56,581				6,559				11.6
Total operating costs and expenses			4,804,440				3,910,730				893,710				22.9
Income from operations			489,278				109,420				379,858				347.2
Other income (expense):
Equity in earnings of SLC Pipeline			1,207				1,025				182				17.8
Interest income			742				694				48				6.9
Interest expense			(31,397	)			(38,745	)			7,348				(19.0	)
Merger transaction costs			(6,014	)			—				(6,014	)			—
			(35,462	)			(37,026	)			1,564				(4.2	)
Income before income taxes			453,816				72,394				381,422				526.9
Income tax provision			160,972				22,982				137,990				600.4
Net income			292,844				49,412				243,432				492.7
Less net income attributable to noncontrolling interest			15,915				11,344				4,571				40.3
Net income attributable to HollyFrontier stockholders		$	276,929			$	38,068			$	238,861				627.5	%
Earnings per share attributable to HollyFrontier stockholders:
Basic		$	5.19			$	0.72			$	4.47				620.8	%
Diluted		$	5.16			$	0.71			$	4.45				626.8	%
Cash dividends declared per common share		$	0.30			$	0.30			$	—				—	%
Average number of common shares outstanding:
Basic			53,336				53,152				184				0.3	%
Diluted			53,643				53,375				268				0.5	%
EBITDA		$	531,696			$	155,682			$	376,014				241.5	%

Balance Sheet Data

		June 30,				December 31,
		2011				2010
		(In thousands)
Cash, cash equivalents and investments in marketable securities		$	517,347			$	230,444
Working capital		$	467,381			$	313,580
Total assets		$	4,165,303			$	3,701,475
Long-term debt		$	838,866			$	810,561
Total equity		$	1,559,188			$	1,288,139

Segment Information

Our operations are currently organized into two reportable segments, Refining and HEP. Our operations that are not included in the Refining and HEP segments are included in Corporate and Other. Intersegment transactions are eliminated in our consolidated financial statements and are included in Consolidations and Eliminations. Prior to the merger, the Refining segment included the operations of our Navajo, Woods Cross and Tulsa refineries and NK Asphalt Partners (“NK Asphalt”). The Refining segment involves the purchase and refining of crude oil and wholesale and branded marketing of refined products, such as gasoline, diesel fuel, jet fuel and specialty lubricant products. The petroleum products produced by the Refining segment are primarily marketed in the Southwest, Rocky Mountain and Mid-Continent regions of the United States and northern Mexico. Additionally, the Refining segment includes specialty lubricant products produced at our Tulsa refinery that are marketed throughout North America and are distributed in Central and South America. NK Asphalt operates various asphalt terminals in Arizona, New Mexico and Texas.

The HEP segment involves all of the operations of HEP. HEP owns and operates a system of petroleum product and crude gathering pipelines in Texas, New Mexico, Oklahoma and Utah, distribution terminals in Texas, New Mexico, Arizona, Utah, Idaho, and Washington and refinery tankage in New Mexico, Utah and Oklahoma. Revenues are generated by charging tariffs for transporting petroleum products and crude oil through its pipelines, by leasing certain pipeline capacity to Alon USA, Inc., by charging fees for terminalling refined products and other hydrocarbons, and storing and providing other services at its storage tanks and terminals. The HEP segment also includes a 25% interest in SLC Pipeline LLC (“SLC Pipeline”) that services refineries in the Salt Lake City, Utah area. Revenues from the HEP segment are earned through transactions with unaffiliated parties for pipeline transportation, rental and terminalling operations as well as revenues relating to pipeline transportation services provided for our refining operations.

														Consolidations
										Corporate				and				Consolidated
		Refining				HEP(1)				and Other				Eliminations				Total
		(In thousands)
Three Months Ended June 30, 2011
Sales and other revenues		$	2,953,226			$	50,940			$	153			$	(37,186	)		$	2,967,133
Depreciation and amortization		$	23,478			$	7,309			$	1,252			$	(207	)		$	31,832
Income (loss) from operations		$	321,032			$	27,692			$	(18,040	)		$	(505	)		$	330,179
Capital expenditures		$	25,152			$	11,425			$	45,690			$	—			$	82,267
Three Months Ended June 30, 2010
Sales and other revenues		$	2,137,361			$	45,483			$	150			$	(37,134	)		$	2,145,860
Depreciation and amortization		$	20,599			$	7,187			$	1,333			$	(295	)		$	28,824
Income (loss) from operations		$	124,549			$	22,888			$	(15,111	)		$	(162	)		$	132,164
Capital expenditures		$	42,492			$	2,576			$	364			$	—			$	45,432
Six Months Ended June 30, 2011
Sales and other revenues		$	5,268,318			$	95,945			$	801			$	(71,346	)		$	5,293,718
Depreciation and amortization		$	46,461			$	14,544			$	2,549			$	(414	)		$	63,140
Income (loss) from operations		$	473,136			$	51,303			$	(34,138	)		$	(1,023	)		$	489,278
Capital expenditures		$	45,784			$	22,900			$	87,621			$	—			$	156,305
Six Months Ended June 30, 2010
Sales and other revenues		$	4,004,534			$	86,172			$	217			$	(70,773	)		$	4,020,150
Depreciation and amortization		$	41,325			$	13,992			$	1,854			$	(590	)		$	56,581
Income (loss) from operations		$	99,969			$	41,149			$	(30,877	)		$	(821	)		$	109,420
Capital expenditures		$	70,764			$	4,487			$	1,279			$	—			$	76,530
June 30, 2011
Cash, cash equivalents and investments in marketable securities		$	—			$	1,402			$	515,945			$	—			$	517,347
Total assets		$	2,614,120			$	678,508			$	901,439			$	(28,764	)		$	4,165,303
Long-term debt		$	—			$	510,566			$	344,996			$	(16,696	)		$	838,866
December 31, 2010
Cash, cash equivalents and investments in marketable securities		$	—			$	403			$	230,041			$	—			$	230,444
Total assets		$	2,490,193			$	669,820			$	573,531			$	(32,069	)		$	3,701,475
Long-term debt		$	—			$	482,271			$	345,215			$	(16,925	)		$	810,561

Refining Operating Data

Prior to the merger, our refinery operations included the Navajo, Woods Cross and Tulsa refineries. The following tables set forth information, including non-GAAP performance measures about our consolidated refinery operations. The cost of products and refinery gross margin do not include the effect of depreciation and amortization. Reconciliations to amounts reported under GAAP are provided under “Reconciliations to Amounts Reported Under Generally Accepted Accounting Principles” below.

		Three Months Ended								Six Months Ended
		June 30,								June 30,
		2011				2010				2011				2010
Navajo Refinery
Crude charge (BPD) (1)			86,080				82,370				78,070				80,650
Refinery throughput (BPD) (2)			94,190				92,440				86,600				91,470
Refinery production (BPD) (3)			93,620				91,750				85,220				89,650
Sales of produced refined products (BPD)			94,340				93,040				87,130				90,000
Sales of refined products (BPD) (4)			98,120				96,280				92,440				93,220
Refinery utilization (5)			86.1	%			82.4	%			78.1	%			80.7	%
Average per produced barrel (6)
Net sales		$	126.36			$	91.21			$	119.35			$	89.70
Cost of products (7)			104.24				82.08				100.30				82.50
Refinery gross margin			22.12				9.13				19.05				7.20
Refinery operating expenses (8)			5.17				4.61				5.71				4.88
Net operating margin		$	16.95			$	4.52			$	13.34			$	2.32
Refinery operating expenses per throughput barrel		$	5.18			$	4.64			$	5.74			$	4.80
Feedstocks:
Sour crude oil			71	%			85	%			72	%			86	%
Sweet crude oil			4	%			4	%			4	%			4	%
Heavy sour crude oil			16	%			—	%			14	%			—	%
Other feedstocks and blends			9	%			11	%			10	%			10	%
Total			100	%			100	%			100	%			100	%
Sales of produced refined products:
Gasolines			52	%			57	%			52	%			57	%
Diesel fuels			32	%			31	%			33	%			31	%
Jet fuels			1	%			5	%			1	%			4	%
Fuel oil			7	%			3	%			6	%			4	%
Asphalt			4	%			2	%			4	%			2	%
LPG and other			4	%			2	%			4	%			2	%
Total			100	%			100	%			100	%			100	%
Woods Cross Refinery
Crude charge (BPD) (1)			26,840				27,450				26,310				26,570
Refinery throughput (BPD) (2)			28,740				28,940				28,320				28,030
Refinery production (BPD) (3)			28,320				28,850				27,480				27,700
Sales of produced refined products (BPD)			27,600				29,070				27,130				28,620
Sales of refined products (BPD) (4)			27,600				29,140				27,170				28,750
Refinery utilization (5)			86.6	%			88.5	%			84.9	%			85.7	%
Average per produced barrel (6)
Net sales		$	128.02			$	96.62			$	118.62			$	93.15
Cost of products (7)			99.79				74.26				94.95				74.48
Refinery gross margin			28.23				22.36				23.67				18.67
Refinery operating expenses (8)			6.16				5.30				6.29				5.74
Net operating margin		$	22.07			$	17.06			$	17.38			$	12.93
Refinery operating expenses per throughput barrel		$	5.92			$	5.32			$	6.03			$	5.86

		Three Months Ended								Six Months Ended
		June 30,								June 30,
		2011				2010				2011				2010
Feedstocks:
Sweet crude oil			61	%			60	%			59	%			60	%
Heavy sour crude oil			5	%			5	%			5	%			6	%
Black wax crude oil			28	%			29	%			29	%			29	%
Other feedstocks and blends			6	%			6	%			7	%			5	%
Total			100	%			100	%			100	%			100	%
Sales of produced refined products:
Gasolines			61	%			62	%			61	%			63	%
Diesel fuels			31	%			31	%			30	%			29	%
Jet fuels			1	%			1	%			1	%			1	%
Fuel oil			3	%			1	%			3	%			1	%
Asphalt			2	%			3	%			3	%			3	%
LPG and other			2	%			2	%			2	%			3	%
Total			100	%			100	%			100	%			100	%
Tulsa Refinery (8)
Crude charge (BPD) (1)			110,100				118,480				107,860				111,080
Refinery throughput (BPD) (2)			111,850				119,800				109,290				112,350
Refinery production (BPD) (3)			110,110				112,860				107,050				107,900
Sales of produced refined products (BPD)			112,710				111,880				106,400				105,360
Sales of refined products (BPD) (4)			114,300				111,880				107,390				106,280
Refinery utilization (5)			88.1	%			94.8	%			86.3	%			88.9	%
Average per produced barrel (6)
Net sales		$	129.11			$	90.93			$	122.65			$	88.74
Cost of products (7)			109.94				81.32				105.53				82.05
Refinery gross margin			19.17				9.61				17.12				6.69
Refinery operating expenses (8)			5.56				4.70				5.76				5.26
Net operating margin		$	13.61			$	4.91			$	11.36			$	1.43
Refinery operating expenses per throughput barrel		$	5.60			$	4.39			$	5.61			$	4.93
Feedstocks:
Sweet crude oil			93	%			89	%			95	%			94	%
Heavy sour crude oil			5	%			3	%			4	%			1	%
Sour crude oil			—	%			8	%			—	%			4	%
Other feedstocks and blends			2	%			—	%			1	%			1	%
Total			100	%			100	%			100	%			100	%
Sales of produced refined products:
Gasolines			38	%			37	%			37	%			39	%
Diesel fuels			30	%			32	%			30	%			31	%
Jet fuels			8	%			9	%			8	%			9	%
Lubricants			10	%			10	%			11	%			10	%
Gas oil / intermediates			6	%			3	%			6	%			3	%
Asphalt			5	%			4	%			5	%			4	%
LPG and other			3	%			5	%			3	%			4	%
Total			100	%			100	%			100	%			100	%

		Three Months Ended								Six Months Ended
		June 30,								June 30,
		2011				2010				2011				2010
Consolidated
Crude charge (BPD) (1)			223,020				228,300				212,240				218,300
Refinery throughput (BPD) (2)			234,780				241,180				224,210				231,850
Refinery production (BPD) (3)			232,050				233,460				219,750				225,250
Sales of produced refined products (BPD)			234,650				233,990				220,660				223,980
Sales of refined products (BPD) (4)			240,020				237,300				227,000				228,250
Refinery utilization (5)			87.1	%			89.2	%			82.9	%			85.3	%
Average per produced barrel (6)
Net sales		$	127.87			$	91.75			$	120.85			$	89.69
Cost of products (7)			106.45				80.74				102.16				81.26
Refinery gross margin			21.42				11.01				18.69				8.43
Refinery operating expenses (8)			5.48				4.74				5.80				5.17
Net operating margin		$	15.94			$	6.27			$	12.89			$	3.26
Refinery operating expenses per throughput barrel		$	5.47			$	4.60			$	5.71			$	4.99
Feedstocks:
Sour crude oil			29	%			37	%			28	%			36	%
Sweet crude oil			54	%			53	%			55	%			55	%
Heavy sour crude oil			9	%			2	%			8	%			1	%
Black wax crude oil			3	%			3	%			4	%			3	%
Other feedstocks and blends			5	%			5	%			5	%			5	%
Total			100	%			100	%			100	%			100	%
Sales of produced refined products:
Gasolines			46	%			48	%			46	%			49	%
Diesel fuels			31	%			32	%			32	%			31	%
Jet fuels			4	%			6	%			4	%			6	%
Fuel oil			3	%			1	%			3	%			2	%
Asphalt			5	%			3	%			4	%			3	%
Lubricants			5	%			5	%			5	%			5	%
Gas oil / intermediates			3	%			2	%			3	%			1	%
LPG and other			3	%			3	%			3	%			3	%
Total			100	%			100	%			100	%			100	%

(1)		Crude charge represents the barrels per day of crude oil processed at our refineries.
(2)		Refinery throughput represents the barrels per day of crude and other refinery feedstocks input to the crude units and other conversion units at our refinery.
(3)		Refinery production represents the barrels per day of refined products yielded from processing crude and other refinery feedstocks through the crude units and other conversion units at our refineries. Refinery production excludes fuel produced for refinery consumption.
(4)		Includes refined products purchased for resale.
(5)		Represents crude charge divided by total crude capacity (BPSD). Our consolidated crude capacity is 256,000 BPSD.
(6)		Represents average per barrel amount for produced refined products sold, which is a non-GAAP measure. Reconciliations to amounts reported under GAAP are provided under “Reconciliations to Amounts Reported Under Generally Accepted Accounting Principles” below.
(7)		Transportation, terminal and refinery storage costs billed from HEP are included in cost of products.
(8)		Represents operating expenses of our refineries, exclusive of depreciation and amortization.

Reconciliations to Amounts Reported Under Generally Accepted Accounting Principles

Reconciliations of earnings before interest, taxes, depreciation and amortization (“EBITDA”) to amounts reported under generally accepted accounting principles in financial statements.

Earnings before interest, taxes, depreciation and amortization, which we refer to as EBITDA, is calculated as net income attributable to HollyFrontier stockholders plus (i) interest expense, net of interest income, (ii) income tax provision, and (iii) depreciation and amortization. EBITDA is not a calculation provided for under accounting principles generally accepted in the United States; however, the amounts included in the EBITDA calculation are derived from amounts included in our consolidated financial statements. EBITDA should not be considered as an alternative to net income or operating income as an indication of our operating performance or as an alternative to operating cash flow as a measure of liquidity. EBITDA is not necessarily comparable to similarly titled measures of other companies. EBITDA is presented here because it is a widely used financial indicator used by investors and analysts to measure performance. EBITDA is also used by our management for internal analysis and as a basis for financial covenants.

Set forth below is our calculation of EBITDA.

		Three Months Ended								Six Months Ended
		June 30,								June 30,
		2011				2010				2011				2010
		(In thousands)
Net income attributable to HollyFrontier stockholders		$	192,235			$	66,162			$	276,929			$	38,068
Add income tax provision			111,961				39,654				160,972				22,982
Add interest expense			15,193				21,023				31,397				38,745
Subtract interest income			(657	)			(635	)			(742	)			(694	)
Add depreciation and amortization			31,832				28,824				63,140				56,581
EBITDA		$	350,564			$	155,028			$	531,696			$	155,682

Reconciliations of refinery operating information (non-GAAP performance measures) to amounts reported under generally accepted accounting principles in financial statements.

Refinery gross margin and net operating margin are non-GAAP performance measures that are used by our management and others to compare our refining performance to that of other companies in our industry. We believe these margin measures are helpful to investors in evaluating our refining performance on a relative and absolute basis.

We calculate refinery gross margin and net operating margin using net sales, cost of products and operating expenses, in each case averaged per produced barrel sold. These two margins do not include the effect of depreciation and amortization. Each of these component performance measures can be reconciled directly to our Consolidated Statements of Income.

Other companies in our industry may not calculate these performance measures in the same manner.

Refinery Gross Margin

Refinery gross margin per barrel is the difference between average net sales price and average cost of products per barrel of produced refined products. Refinery gross margin for each of our refineries and for all of our refineries on a consolidated basis is calculated as shown below.

		Three Months Ended								Six Months Ended
		June 30,								June 30,
		2011				2010				2011				2010
Average per produced barrel:
Navajo Refinery
Net sales		$	126.36			$	91.21			$	119.35			$	89.70
Less cost of products			104.24				82.08				100.30				82.50
Refinery gross margin		$	22.12			$	9.13			$	19.05			$	7.20
Woods Cross Refinery
Net sales		$	128.02			$	96.62			$	118.62			$	93.15
Less cost of products			99.79				74.26				94.95				74.48
Refinery gross margin		$	28.23			$	22.36			$	23.67			$	18.67
Tulsa Refinery
Net sales		$	129.11			$	90.93			$	122.65			$	88.74
Less cost of products			109.94				81.32				105.53				82.05
Refinery gross margin		$	19.17			$	9.61			$	17.12			$	6.69
Consolidated
Net sales		$	127.87			$	91.75			$	120.85			$	89.69
Less cost of products			106.45				80.74				102.16				81.26
Refinery gross margin		$	21.42			$	11.01			$	18.69			$	8.43

Net Operating Margin

Net operating margin per barrel is the difference between refinery gross margin and refinery operating expenses per barrel of produced refined products. Net operating margin for each of our refineries and for all of our refineries on a consolidated basis is calculated as shown below.

		Three Months Ended								Six Months Ended
		June 30,								June 30,
		2011				2010				2011				2010
Average per produced barrel:
Navajo Refinery
Refinery gross margin		$	22.12			$	9.13			$	19.05			$	7.20
Less refinery operating expenses			5.17				4.61				5.71				4.88
Net operating margin		$	16.95			$	4.52			$	13.34			$	2.32
Woods Cross Refinery
Refinery gross margin		$	28.23			$	22.36			$	23.67			$	18.67
Less refinery operating expenses			6.16				5.30				6.29				5.74
Net operating margin		$	22.07			$	17.06			$	17.38			$	12.93
Tulsa Refinery
Refinery gross margin		$	19.17			$	9.61			$	17.12			$	6.69
Less refinery operating expenses			5.56				4.70				5.76				5.26
Net operating margin		$	13.61			$	4.91			$	11.36			$	1.43
Consolidated
Refinery gross margin		$	21.42			$	11.01			$	18.69			$	8.43
Less refinery operating expenses			5.48				4.74				5.80				5.17
Net operating margin		$	15.94			$	6.27			$	12.89			$	3.26

Below are reconciliations to our Consolidated Statements of Income for (i) net sales, cost of products and operating expenses, in each case averaged per produced barrel sold, and (ii) net operating margin and refinery gross margin. Due to rounding of reported numbers, some amounts may not calculate exactly.

Reconciliations of refined product sales from produced products sold to total sales and other revenues

		Three Months Ended								Six Months Ended
		June 30,								June 30,
		2011				2010				2011				2010
		(Dollars in thousands, except per barrel amounts)
Navajo Refinery
Average sales price per produced barrel sold		$	126.36			$	91.21			$	119.35			$	89.70
Times sales of produced refined products sold (BPD)			94,340				93,040				87,130				90,000
Times number of days in period			91				91				181				181
Refined product sales from produced products sold		$	1,084,793			$	772,242			$	1,882,213			$	1,461,213
Woods Cross Refinery
Average sales price per produced barrel sold		$	128.02			$	96.62			$	118.62			$	93.15
Times sales of produced refined products sold (BPD)			27,600				29,070				27,130				28,620
Times number of days in period			91				91				181				181
Refined product sales from produced products sold		$	321,535			$	255,596			$	582,487			$	482,537
Tulsa Refinery
Average sales price per produced barrel sold		$	129.11			$	90.93			$	122.65			$	88.74
Times sales of produced refined products sold (BPD)			112,710				111,880				106,400				105,360
Times number of days in period			91				91				181				181
Refined product sales from produced products sold		$	1,324,231			$	925,766			$	2,362,043			$	1,692,286
Sum of refined product sales from produced products sold from our three refineries (1)		$	2,730,559			$	1,953,604			$	4,826,743			$	3,636,036
Add refined product sales from purchased products and rounding (2)			63,038				27,296				138,659				68,680
Total refined product sales			2,793,597				1,980,900				4,965,402				3,704,716
Add direct sales of excess crude oil (3)			138,492				114,155				273,901				249,017
Add other refining segment revenue (4)			21,137				42,306				29,015				50,801
Total refining segment revenue			2,953,226				2,137,361				5,268,318				4,004,534
Add HEP segment sales and other revenues			50,940				45,483				95,945				86,172
Add corporate and other revenues			153				150				801				217
Subtract consolidations and eliminations			(37,186	)			(37,134	)			(71,346	)			(70,773	)
Sales and other revenues		$	2,967,133			$	2,145,860			$	5,293,718			$	4,020,150