North Dakota Bakken Estimated Reserve Model Raised 20 Percent to 518,000 Barrels Per Well ND Bakken Production More than Double First Quarter of 2009 Company Increases Bakken Lease Position to 773,053 Net Acres

First Quarter Conference Call Scheduled for Thursday, May 6, 2010 at 10 a.m. ET

Ten Early 2010 Bakken Wells Average 1,345 Boe in Initial One-Day Tests

2009 Proved Reserves Increase 62 percent, Replacing 811 Percent of 2009 Production Capital Expenditure Budget Increased 31 Percent to $850 Million to Accelerate Drilling Successful Anadarko Woodford Drilling Extends Cana Play Potential 40 Miles Northwest

Hendrickson 1-36H Sets New Company Production Record for Bakken Company-Operated 4Q09 Three Forks/Sanish Wells Average 1,242 Barrels of Oil Equivalent per Day

Third Quarter Operating and Net Income Are Double Those for Second Quarter 2009 Company Accelerating Drilling Operations in Fourth Quarter 2009 $650 Million Capital Budget Expected to Boost Production Approximately 10 Percent in 2010

Additional Oklahoma Anadarko Woodford and North Dakota Bakken Wells Announced

Mathistad 2-35H 'Companion Well' Yields Record Initial Production of 995 Boepd

Company Reports Record Wells in Middle Bakken and Three Forks/Sanish Zones in North Dakota 2009 Capital Expenditure Budget Raised 42 Percent to $390 Million

2009 Capital Expenditure Budget Reduced in Line with Cash Flow Outlook

2009 Outlook for Production Growth and Capital Expenditures