Rosetta Resources 8-K Regulation FD Disclosure

Exhibit 99.1

2009

2

2008 Achievements

§Successful resolution of Calpine litigation

§Significant progress on strategy shift to onshore unconventional player

§Established experienced team and filled key functions

§Initiated comprehensive resource assessments and reviews of existing
asset positions

§Increased project inventory by ~150%

§Entered several new unconventional plays with substantial upside from
meaningful positions

§Completed four property acquisitions

3

Transition to Resource Player Underway

§Expanded Acreage Position

§Quality Proved Reserve Base

§Significant Project Inventory

§Additional Resource Potential

§Focus on Cost Control

§Financial Flexibility

4

Expanded Acreage Position

Reserves & Inventory

6

2008 Year End Reserves

7

PDP 235.1 Bcfe

PDNP 92.2 Bcfe

PUD 70.9 Bcfe

Proved Reserves by District (Bcfe)

8

2008 Year End Capital Inventory

9

Well Count

1158

Resource Size (Bcfe)

299

Resource Inventory

10

Green River Basin: Constellation / Nielson
Purchase Price	$39 million
WI / NRI	100% / 78%
Net Acres	1280
Producing Well Count	28
Net Production	9 Mcfe/d
Net Proven Developed	30 Bcfe
Acquisition Cost	$1.30 / Mcfe
Total Net Non-Proven	178 Bcfe

ALONG THE PINEDALE ANTICLINE:Rosetta closed on (2) producing property acquisitions that
offered not only proven reserves and immediate cashflows, but a significant capital inventory of
opportunities that are held by production and will be developed at the company’s discretion…

PINEDALE FIELD

90 sq.mi.

>600 wells

700 MMcfe/d

OGIP: 48 TCFE

Recoverable: 27 TCFE

JONAH FIELD

35 sq.mi.

>1,000 wells

900 MMcfe/d

OGIP: 14 TCFE

Recoverable: 9 TCFE

11

South Texas: Constellation
Purchase Price	$20 million
WI / NRI	70% / 52%
Net Acres	21,110
Producing Well Count	285
Net Production	5 Mcfe/d
Net Proven Developed	14 Bcfe
Acquisition Cost	$1.43 / Mcfe
Total Net Non-Proven	39 Bcfe

IN THE GREATER MAVERICK BASIN:Rosetta closed on (1) producing property acquisition
that offered not only proven reserves and immediate cashflows, but a significant capital
inventory of opportunities that are mostly held by production and will be developed at the
company’s discretion…

Additional Resource
PotentialBeyond Reserves & Inventory

13

Additional Resource Potential
Beyond Reserves & Inventory

§Organic Growth

•Denver Julesburg Basin Niobrara Chalk

•Sacramento Basin Tight Capay Sand

•South Texas Eagle Ford Shale

•Alberta Basin Bakken Shale

14

30 miles

Denver

Denver Julesburg Basin Niobrara Play

Rosetta Resource’s Position:

▪ Net Undeveloped Acreage: 90,000 acres

▪Net Projects:1750 wells*

▪ Net Resource Potential:350 Bcfe

* Not including the 500 locations already in inventory

Denver Julesburg Basin

15

Denver Julesburg Basin
Niobrara Downspacing Project

16

Sacramento BasinTight Capay Resource Play

Sacramento Basin Tight Capay Sand Play

Rosetta Resource’s Position:

▪ Net Undeveloped Acreage: 30,000 acres

▪ Net Projects:375 wells

▪ Net Resource Potential:100 Bcfe

17

Sacramento BasinTight Capay Resource Play

WELL RESULTS
Well	Initial Rate (Mcfe/d)
RVGU 242	475
RVGU 222	200
RVGU 296	130
RVGU 299	1300
Jordan 8	1250
RVGU 269U	550
Average	650

18

South Texas
Eagle Ford Shale Play

19

South Texas
Eagle Ford Shale Play

South Texas Eagle Ford Shale Play

Rosetta Resource’s Position:

▪ Net Undeveloped Acreage: 25,000 acres

▪ Net Projects:150 wells

▪ Net Resource Potential:300 Bcfe

20

Alberta Basin
Bakken Shale Resource Play

Alberta Basin Bakken Play

Rosetta Resource’s Position:

▪ Net Undeveloped Acreage:231,000 acres

▪ Net Projects:723 wells*

▪ Net Resource Potential: 60 - - 300 MMBOE

* 320 acre development

21

Growth OpportunitiesSummary of Projects in Addition to Our PUD, Probable & Possible Inventories

	Areal Extent (Net Acres)	Projects (Project Count)	Net Resource (Bcfe)
DJ Basin Niobrara Chalk	90,000	1750	350
California Tight Capay Sand	30,000	375	100
South Texas Eagle Ford Shale	25,000	150	300
Alberta Basin Bakken Shale	230,000	700	600
TOTAL	375,000	2975	1350

22

Combined Opportunities
Inventory + Additional Resource Potential

Service Costs

24

☑	Drilling rig rates (incl. mob/demob/fuel and power) - Down 24% from 4Q 2008
☑	Tubulars - spot market supply
	▪Down ~41% since peak in Q3-2008
	▪Down ~2% since Q4-2008
r	Stimulation
r	Cementing
r	Equipment rentals
r	Wireline
r	Drilling mud
r	Other
☑	Seismic - 120 sq. mile shoot in South Texas ~$5.5MM vs. ~$8MM bid in early 2008

§Major areas of savings

▪ Initial market price reduction captured

▪ Should continue to decline as broad pullback in
activity adds price pressure

Reduce Capex by Bidding Out Major Services and Supplies

25

r	Equipment Rentals (mainly compression)
☑	Chemicals - Pricing down 13% vs. 2008
r	Contract labor / consulting
r	Salt water disposal / water hauling
r	Reduction in LOE in non-operated properties

Continue to Drive Down LOE Costs

Approx. ~$4MM of opportunities identified to lower the current LOE budget
of $40MM.

§Major areas of savings

Financial Summary

27

Financial Capacity to Grow

§Revolving line of credit - conforming borrowing base remains at $400
million

§$300 million debt outstanding at year end 2008

§~$200 million liquidity from unused capacity and cash on hand

§Protected 2009 natural gas production with 52 BBtu/d swapped at an
average price of $7.65 and 5 BBtu/d of collars at $8.00 by $10.05

§Protected 2010 natural gas production of 10 BBtu/d swapped at $8.31

§Goal to maintain optionality and flexibility

28

$0.00

$2.00

$4.00

$6.00

$8.00

$10.00

$12.00

$14.00

$16.00

1/1/2008

4/1/2008

7/1/2008

10/1/2008

1/1/2009

4/1/2009

7/1/2009

NYMEX Gas

Rosetta Investment Deck

Strip > ROSE Price Deck

■ Preference for organic activities

■ Ramp up drilling in existing assets and convert
price-sensitive inventory

■ Consider adding hedges

■ Maintain financial discipline to position for cycles

Strip < ROSE Price Deck

■ Preference for inorganic activities

■ Ramp up asset studies to build inventory

■ Maintain flexibility to respond to environment

Flexibility - How Will We Act?

29

2009 Business Plan

§Maintain balance between cash flow and capital activity

§Re-engineer existing opportunity set

•Sacramento Basin workovers

•Lobo program

§Pursue bolt-on/strategic acquisitions

§Evaluate new play opportunities

•Eagle Ford

•Bakken

§Evaluate sale of non-core assets

§Focus on cost reductions

30

It’s a Great Time to Look at Rosetta

§Post-Calpine reserves and financial position is high quality

§Unconventional approach on existing assets will be impactful

§Ground floor opportunity to participate in significant new play
entry

§Experienced management with passion and commitment

§Very attractive risk-reward profile for Company our size

§Today trading at significant discount on valuation basis to
companies with similar business model