Canadian markets' risk and returns reflect the performance of mining ventures because of their broad representation in the value of these markets. Within this overall dynamic framework, a mining venture's risk resolution and the resulting effects on the venture's valuation are critical to its short- and long-term success in attracting investors. Conventional methods uses a single risk-adjusted rate to account for venture risk, and thus tend to be biased against long-term ventures. The use of a single rate implies that the term structure of interest rates, market price of mineral commodity risks, and the risks of future net cash flows are known and stationary. In reality, the risk structure of a long-term mining venture varies with changes in the sources and magnitudes of the underlying uncertainities. These changes are reflected in the venture's market and operating risks, but are neglected in conventional methods resulting in severe under-estimation of long-term cash flows. In this study, the authors develop the dynamic risk model (DRM) for valuing long-term, multi-phase mining ventures, which overcomes the limitations of conventional methods. This model uses the variance sensitivity ratio (VSR) in the capital market to derive the expected venture return and values from the venture and market risk structures. The derived risks and uncertainities and their resoltuion over time. The DRM is used to assess the Moose Gold Venture on the Toronto Stock Exchange (TSE 300). Analysis of the results shows that, for long-term multi-phase ventures with varying uncertainities, the use of single rates significantly penalizes long-term cash flows. Pronouced effects of this problem and delays result in the loss of substantial value, which may lead to the rejection of profitable ventures. The authors also show that effective exploration and development programs and diversification allow investors to significantly reduce or eliminate the venture's operating risks, and maximize its market value.The dynamic risk model (DRM) has been developed for valuing long-term, multi-phase mining ventures. This model uses the variance sensitivity ratio (VSR) in the capital market to derive the expected venture and market risk structures. The derived values are simulated to capture the underlying risks and uncertainties and their resolution over time. The DRM is used to assess the Moose Gold Venture on the Toronto Stock Exchange (TSE 300). Analysis of the results shows that, for long-term multi-phase ventures with varying uncertainties, the use of single rates significantly penalizes long-term cash flows. It is also shown that effective exploration and development programs and diversification allow investors to significantly reduce or eliminate the venture's operating risks, and maximize its market value.