Rainy River Announces Updated Resource Estimate of 2.37 Moz Indicated and 2.66 Moz Inferred Gold

VANCOUVER, BRITISH COLUMBIA--(Marketwire - March 2, 2010) - Rainy River Resources Ltd. (TSX VENTURE:RR) -

Highlights:

• Significantly increased inferred and indicated gold resources
• Average gold grades increased with same cutoff grades as per 2009 estimate
• Underground indicated contained gold increases +147%
• Underground inferred contained gold increases +388%

Rainy River Resources Ltd. (the "Company" or "Rainy") is pleased to announce that it has received an independent mineral resource estimate prepared by SRK Consulting (Canada) Inc. ("SRK") for the Company's Rainy River property in northern Ontario. This updated mineral resource statement is reported in accordance with Canadian Securities Administrator's National Instrument 43-101 and was estimated in conformity with generally accepted CIM "Estimation of Mineral Resource and Mineral Reserves Best Practices" Guidelines, including the critical requirement that all mineral resources "have reasonable prospects for economic extraction". The Company does not consider the increase in resources to be material and therefore will not be filing a new technical report prior to the publication of the Preliminary Economic Assessment technical report later in 2010.

The addition of 124 diamond drill holes (68,453 metres) from the 2009 drilling campaign has resulted in an overall increase in gold resources to 2.37 Moz gold in the indicated category and 2.66 Moz gold in the inferred category. The company's focus of defining mineralization below the limits of the proposed open pit has successfully increased total underground gold resources to 935,000 ounces in all classes, a 298% increase over the 2009 NI 43-101 estimate. The consolidated mineral resource statement as prepared by SRK Consulting Ltd is detailed in Table 1.

Pit Optimization for Reporting of Resources

CIM Definition Standards for Mineral Resources and Mineral Reserves (December 2005) defines a mineral resource as:

"a concentration or occurrence of diamonds, natural solid inorganic material, or natural solid fossilized organic material including base and precious metals, coal, and industrial minerals in or on the Earth's crust in such form and quantity and of such a grade or quality that it has reasonable prospects for economic extraction. The location, quantity, grade, geological characteristics and continuity of a Mineral Resource are known, estimated or interpreted from specific geological evidence and knowledge".

The "reasonable prospects for economic extraction" requirement generally implies that the quantity and grade estimates meet certain economic thresholds and that the mineral resources are reported at an appropriate cut-off grade taking into account extraction scenarios and processing recoveries. The reader is cautioned that the results from the pit optimization are used solely for the purpose of reporting mineral resources that have "reasonable prospects for economic extraction" by an open pit and do not represent a thorough economic study as is required to evaluate mineral reserves.

In accordance with these guidelines the Company elected to use more stringent parameters for determining the depth and extent of the conceptual pit for the purposes of reporting as open pit and underground amenable resources. A comparison of these assumptions from 2009 and 2010 is outlined in Table 2. These assumptions are based upon benchmarking with similar projects in preparation for the Company's upcoming preliminary economic assessment. Of particular note is the change to a shallower pit depth.

Addition of Ounces (Potential Underground Amenable Resources)

Open pit resources increased to a limited degree in the 2010 estimate due to the change to a shallower pit model and also because the new South Zone was not included in the estimate. The most significant addition of contained gold can be attributed to the extensive yet widely spaced drilling that was performed in 2009 at depths below the conceptual pit bottom. This includes the ODM "Deeps", 433 Zone and the newly discovered high grade Beaver Pond depth extensions. Both tonnage and grade enhancements account for a +147% increase in indicated contained gold as compared to the previous estimate performed by SRK in 2009. As well, the addition of inferred ounces below the conceptual pit allowed for a tonnage increase of +396% (despite a -1% loss of gold grade) resulting in a +388% increase in inferred gold ounces. Factors that may have contributed to these net gains are:

1. Relatively small underground resource component reported in 2009;
2. New optimization parameters raised the base of the conceptual shell used for resource reporting by 30 metres transferring previous open pit resources to underground;
3. New drill data has allowed extensions to high grade zones below the conceptual pit; and
4. Increased contribution of inferred underground resources within sparsely drilled high grade resource domains.

A comparison between the open pit and underground reported resources for the 2009 and 2010 SRK resource estimates is presented in Table 3.

2010 Underground versus Open Pit Grade Tonnage Comparison

Grade tonnage tables for the potential open pit and underground amenable resources are detailed in Tables 4 and 5 respectively.

Comments:

"We are very pleased to report a very significant overall increase of gold resources," commented Raymond Threlkeld, President and CEO. "The newly discovered South Zone was not sufficiently drilled to be included into the potential pit and further exploration of that zone will increase the resource confidence as well as expanding the strike length to the west. We will be focusing our 2010 efforts to discovery of shallow resources along the extensive gold geochemical anomaly to the west of the main Beaver Pond- ODM17 Zone and bringing our higher grade 433 and BP underground resources to a higher confidence level. We are also completing geophysical surveys and geologic compilation to target our potential for gold rich VMS deposits in the Richardson caldera."

About Rainy River Resources Ltd.

Rainy River Resources is a Canadian precious metals exploration company whose key asset is the Rainy River gold project. With CAN$69 million in its treasury, the Company is well funded to conduct a dual-focused drilling program consisting of: 1) definition diamond drilling of the main gold resources in preparation for scoping and pre-feasibility studies, and 2) selective diamond drill testing of high-priority gold targets defined primarily by RC drilling within the large gold system centered in Richardson Township. The Company's property is extremely well located in the southwestern corner of northern Ontario near the U.S. border. It is accessed by a network of roads and is close to hydro-electric infrastructure. The Rainy River district has a skilled labour force and is one of the lowest-cost areas for mineral exploration and development. Ontario has low political risk and, according to the annual Fraser Institute global survey of the mining industry, has consistently ranked as one of the top jurisdictions embracing mineral development.

RAINY RIVER RESOURCES LTD.

Raymond W. Threlkeld, President & CEO

This release includes certain statements that may be deemed to be "forward-looking statements". All statements in this release, other than statements of historical fact, that address events or developments that the Company expects to occur, are forward looking statements. Forward looking statements are statements that are not historical facts and are generally, but not always, identified by the words "expects", "plans", "anticipates", "believes", "intends", "estimates", "projects", "potential" and similar expressions, or that events or conditions "will", "would", "may", "could" or "should" occur. Although the Company believes the expectations expressed in such forward-looking statements are based on reasonable assumptions, such statements are not guarantees of future performance and actual results may differ materially from those in forward looking statements. Factors that could cause the actual results to differ materially from those in forward-looking statements include gold prices, results of exploration and development activities, regulatory changes, defects in title, availability of materials and equipment, timeliness of government approvals, continued availability of capital and financing and general economic, market or business conditions. The Company cautions that the foregoing list of important factors is not exhaustive. Investors and others who base themselves on the Company's forward-looking statements should carefully consider the above factors as well as the uncertainties they represent and the risk they entail. The Company believes that the expectations reflected in those forward-looking statements are reasonable, but no assurance can be given that these expectations will prove to be correct. Please see the public filings of the Company at www.sedar.com for further information.

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