Rocky Mountain Region

Whiting plans to drill up to 80 wells in the Rockies during 2006. At year-end 2005, the Rockies contained approximately 22% of our total proved reserves and represented about 29% of our average daily production. We hold a total of approximately 22% of our total proved reserves and represented about 29% of our average production. We hold a total of approximately 410,000 net acres in the region, primarily in the Williston, Green River and Piceance basins.

Williston Basin

MIDDLE BAKKEN PLAY—Middle Bakken formation reserves are contained in stratigraphic traps in dolomitic siltstone that are most effectively penetrated with horizontal drilling. Whiting's Bakken operations are concentrated in three areas: in Richland County, Montana; in the Billings Nose area of Billings County, North Dakota; and, in the Company's Robinson Lake area of Mountrail County, North Dakota. In aggregate, we drilled or participated in nine horizontal Bakken wells in 2005 of which eight were completed as producers. Estimated proved reserves averaged more than 300 MBOE per well at a completed cost of approximately $3.0 million.

In 2006, we plan to drill a total of 10 Middle Bakken wells with single, dual or tri-laterals on 640-acre or 1,280-acre spacing. Reserves for these wells are estimated to be approximately 350 MBOE with completed well costs of between $3.0 million and $3.5 million.

HORIZONTAL NISKU "A" PLAY—Whiting completed a significant exploratory discovery in the Nisku "A" Formation in the third quarter of 2004 and continues to exploit the play in Billings and Golden Valley counties, North Dakota. The Nisku "A" is a thin dolomite zone found at a depth of approximately 10,500 feet. While thin, the zone has a large aerial extent that is an ideal horizontal drilling target. In 2005, we drilled eight casing-exit horizontal wells and 13 grass-roots horizontal wells. Gross production at year-end 2005 from the Nisku "A" was approximately 1,630 barrels of oil and 1.0 MMcf of gas per day. Whiting holds working interests of between 25% and 90% in Nisku "A" wells and plans to drill up to nine grass-roots horizontal wells in 2006. Estimated proved reserves for these wells are approximately 350 MBOE with completed well costs of about $3.6 million.
Green River Basin

SIBERIA RIDGE FIELD—The Siberia Ridge field is located in the Sweetwater County, Wyoming portion of the Greater Green River Basin. In 2005, we drilled five wells to the Almond Formation at approximately 10,500 feet. Four of the five wells were completed as producers in early 2006. Initial production rates from these wells averaged approximately 1.3 Bcf of gas per well. We have identified an additional 44 potential locations in the field and plan to drill up to nine new wells during 2006. The Company holds working interests in the Siberia Ridge field of between 50% and 100%. HIAWATHA WEST FIELD - Whiting drilled 11 wells in Hiawatha West field during 2005, and all 11 were completed as producers in 2005 and early 2006. At year-end 2005, these wells were producing at a combined average gross rate of approximately 3.4 MMcf of gas per day primarily from the Lewis Formation at a depth of about 5,000 feet. The Company holds a 91% working interest in the field, which is located in the Moffat County, Colorado portion of the Green River Basin. Whiting plans to drill five more development wells in Hiawatha West field in 2006.
Piceance Basin

SULPHUR CREEK PROSPECT—Whiting plans to drill its first wells in the Piceance Basin at its Sulphur Creek prospect, located in the heart of the Basin in Rio Blanco County, Colorado. A total of 76 drilling locations have been identified on 20-acre spacing. These wells will target the Williams Fork Formation at a depth of approximately 7,000 feet. Reserve potential is estimated at between 2.0 Bcf and 2.5 Bcf per well with a completed well cost of approximately $2.9 million.

Whiting will be operator of the drilling program, holding a 50% working interest, and plans to drill four to six wells from each drilling pad. Our acreage at Sulphur Creek is located along a valley floor, providing easy access to the Company's drilling locations as well as lower well costs and fewer drilling challenges than those wells drilled atop the neighboring mesas. If our drilling activity is successful, we also plan to build an eight-mile natural gas pipeline that would connect to five interstate pipelines with access to major gas markets, providing the opportunity for the Company to capture the best possible price.