SUPPLEMENTAL RESERVE INFORMATION

Reserve Reporting and Determination Methodologies

All reports, including our U.S. reserves, were evaluated using Canadian NI 51-101 rules. Three external, independent third party engineering firms were used to evaluate and review our reserves this year. Sproule Associates Limited ("Sproule"), our historical independent engineering evaluators, evaluated our Canadian conventional reserves. GLJ Petroleum Consultants Ltd. ("GLJ") evaluated the Joslyn SAGD bitumen reserves as they have previously performed such evaluations for the operator of the Joslyn project. DeGolyer and MacNaughton ("D&M") of Dallas, Texas, evaluated the reserves attributed to our assets in the United States. Sproule evaluated 90% of the total proved plus probable value (discounted at 10%) of our Canadian conventional year-end reserves and has reviewed the remainder of the reserves internally evaluated by Enerplus. Both GLJ and D&M evaluated 100% of the reserves in their respective areas. Both GLJ and D&M utilized Sproule's forecast price and cost assumptions as of December 31, 2006 in their evaluations to maintain consistency among our reserve reporting.

The following tables report company interest reserves that include gross working interest reserves plus owned royalty interest reserves using forecast prices. "Company interest" reserves are not a measure defined in NI 51-101 adopted by the Canadian securities regulators and does not have a standardized meaning under NI 51-101. Accordingly, our company interest reserves may not be comparable to reserves presented or disclosed by other issuers. Our reserves statement, which includes complete disclosure of our oil and gas reserves and other oil and gas information in accordance with NI 51-101, is contained within our Annual Information Form available on our website at www.enerplus.com and on our SEDAR profile at www.sedar.com. Additionally, the Annual Information Form is part of our Form 40-F that is filed with the SEC and available on www.sec.gov.

Probable reserves are evaluated and categorized by our third party engineering firms or our own internal evaluators under the review of the third party engineering firm. Care should be used when comparing U.S. and Canadian style reserves and production reporting between companies. Under U.S. reporting, reserve estimates are calculated using prices and costs held constant at amounts in effect at the date of the reserve report and typically only include net proved reserves. Additionally, proved reserve standards in the U.S. may not be comparable to the Canadian standards. Generally, Canadian standards for reporting proved reserves may be more conservative than U.S. standards.

All evaluations of future net production revenues set forth in the tables are stated after the provision for income taxes and exclude abandonment costs on wells and facilities where reserves are not assigned or associated general and administrative costs. These schedules have been prepared on the basis that Enerplus will not pay cash income taxes in Canada in the future due to Enerplus' current structure as an income trust and Canadian tax laws currently in effect. Under our current mutual fund structure and existing tax legislation in Canada, annual taxable income is transferred from our operating entities to the Fund through interest, royalty and other payments. We, in turn, make distributions to our unitholders and therefore currently do not incur any Canadian income tax. As a result, after tax future net revenues from Canadian oil and gas reserves are equal to before tax future net revenues from Canadian oil and gas reserves. Enerplus' U.S. operations are subject to cash income taxes, and as a result Enerplus' U.S. reserves are shown net of the effect of such taxes that we estimate would be payable after taking into account inter-company debt in our structure. The Canadian federal government has announced a proposal designed to effectively tax income trusts such as Enerplus at the same level as Canadian corporations, effective for the 2011 tax year. Such proposal has not yet been approved or put in force and it is uncertain as what form, if any, changes in Canadian income tax laws will take as a result of such proposal. Any changes in Canadian income tax laws that may result from such proposal could adversely affect the estimated future net revenues associated with Enerplus' oil and gas reserves. For additional information, investors should refer to disclosure contained under the headings General Development of Enerplus Resources Fund and Risk Factors - Risks Relating to Enerplus' Structure and Ownership of the Trust Units' in Enerplus' Annual Information Form.

The net estimated present value of all future net revenues at December 31, 2006 was based upon crude oil and natural gas pricing assumptions prepared by Sproule as of December 31, 2006. These prices were applied to the reserves evaluated by Sproule, GLJ and D&M. The base reference prices and exchange rates used by Sproule are detailed below:

⁽¹⁾ Edmonton refinery postings for 40 degree API, 0.4% sulphur content crude
⁽²⁾ The bitumen price is derived by GLJ from Sproule's forecasts of various stream prices
** Escalation varies after 2011

RESERVES SUMMARY

The following table sets out our company interest volumes by production type and reserve category under a forecast price scenario. Under different price scenarios, these reserves could vary as a change in price can affect the economic limit and reserves associated with a property.

2006 Reserves Summary - Company Interest Volumes (Forecast Prices)

RESERVES RECONCILIATION

2006 Proved Reserves- Company Interest Volumes (Forecast Prices)