y All permitting and/or contractual requirements necessary for us to have the right to or control of the future benefit from the targeted ore body  have been met. y Authorization of development of the ore body by management and/or the Board of Directors; and y  Recognize the funded status of our defined benefit plans in our consolidated financial statements; and y Recognize as a component of other comprehensive income (loss) the actuarial gains and losses and prior service costs and credits that arise  during the period but are not immediately recognized as components of net periodic benefit cost. F-8 [ HL:10-K Regulations regarding employers’ accounting for defined benefit pension and other post-retirement plans among other things, require us to: K. Pension Plans and Other Post-retirement Benefits  – We maintain pension plans covering substantially all U.S. employees and provide certain  post-retirement benefits for qualifying retired employees. Pension benefits generally depend on length and level of service and age upon retirement.  Substantially all benefits are paid through pension trusts. We contributed approximately $0.3 million related to our unfunded supplemental executive  retirement plan in years 2012, 2011 and 2010, and expect to contribute $0.3 million related to this plan in 2013. We did not contribute to our other  pension plans during 2011, but contributed approximately $1.1 million to the Hecla pension plan in 2012 and expect to contribute $1.0 million to our  defined benefit plans in 2013. Declines in the market prices of metals, increased production or capital costs, reduction in the grade or tonnage of the deposit or an increase in the  dilution of the ore or reduced recovery rates may render ore reserves uneconomic to exploit. If our realized price for the metals we produce were to  decline substantially below the levels set for calculation of reserves for an extended period, there could be material delays in the development of new  projects, net losses, reduced cash flow, restatements or reductions in reserves and asset write-downs in the applicable accounting periods. Reserves  should not be interpreted as assurances of mine life or of the profitability of current or future operations. No assurance can be given that the estimate  of the amount of metal or the indicated level of recovery of these metals will be realized. Reserve estimates will change as existing reserves are depleted through production and as production costs and/or metals prices change. A  significant drop in metals prices may reduce reserves by making some portion of such ore uneconomic to develop and produce. Changes in reserves  may also reflect that actual grades of ore processed may be different from stated reserve grades because of variation in grades in areas mined, mining  dilution and other factors. Our reserve estimates may change based on actual production experience. It is reasonably possible that certain of our  estimates of proven and probable ore reserves will change in the near term, which could result in a change to estimated future cash flows, associated  carrying values of the asset and amortization rates in future reporting periods, among other things. J. Proven and Probable Ore Reserves  –  At least annually, management reviews the reserves used to estimate the quantities and grades of ore at  our mines which we believe can be recovered and sold economically. Management’s calculations of proven and probable ore reserves are based on  engineering and geological estimates, including future metals prices and operating costs. From time to time, management obtains external audits of  reserves. A partial third-party audit of 2012 reserves at Greens Creek was concluded during 2012. Although management has made a reasonable estimate of factors based on current conditions and information, assumptions underlying future cash  flows are subject to significant risks and uncertainties. Estimates of undiscounted future cash flows are dependent upon estimates of metals to be  recovered from proven and probable ore reserves, and to some extent, identified resources beyond proven and probable reserves, future production  and capital costs and estimated metals prices (considering current and historical prices, forward pricing curves and related factors) over the estimated  remaining mine life. It is reasonably possible that changes could occur in the near term that could adversely affect our estimate of future cash flows to  be generated from our operating properties. If undiscounted cash flows including an asset’s fair value are less than the carrying value of a property, an  impairment loss is recognized. I. Impairment of Long-lived Assets –  Management reviews and evaluates the net carrying value of all facilities, including idle facilities, for  impairment upon the occurrence of other events or changes in circumstances that indicate that the related carrying amounts may not be recoverable.  We estimate the net realizable value of each property based on the estimated undiscounted future cash flows that will be generated from operations  at each property, the estimated salvage value of the surface plant and equipment, and the value associated with property interests. Undeveloped mineral interests are not amortized until such time as there is proven and probable reserves. At that time, the basis of the mineral  interest is amortized on a units-of-production basis. Pursuant to our policy on impairment of long-lived assets (discussed further below), if it is  determined that an undeveloped mineral interest cannot be economically converted to proven and probable reserves, the basis of the mineral interest  is reduced to its net realizable value and an impairment loss is recorded to expense in the period in which it is determined to be impaired. H. Depreciation, Depletion and Amortization –  Capitalized costs are depreciated or depleted using the straight-line method or unit-of- production method at rates sufficient to depreciate such costs over the shorter of estimated productive lives of such facilities or the useful life of the  individual assets. Productive lives range from 1 to 26 years, but do not exceed the useful life of the individual asset. Determination of expected useful  lives for amortization calculations are made on a property-by-property or asset-by-asset basis at least annually. Our estimates for reserves, mineralized  material, and other resources are a key component in determining our units of production depreciation rates. Our estimates of proven and probable  ore reserves, mineralized material, and other resources may change, possibly in the near term, resulting in changes to depreciation, depletion and  amortization rates in future reporting periods. Included in property, plant and equipment on our consolidated financial statements are mineral interests, which are tangible assets that include  acquired undeveloped mineral interests and royalty interests. Undeveloped mineral interests include: (i) mineralized material and other resources which  are measured, indicated or inferred with insufficient drill spacing or quality to qualify as proven and probable reserves; and (ii) inferred material not  immediately adjacent to existing proven and probable reserves but accessible within the immediate mine infrastructure. Residual values for  undeveloped mineral interests represents the expected fair value of the interests at the time we plan to convert, develop, further explore or dispose of  the interests and are evaluated at least annually. When assets are retired or sold, the costs and related allowances for depreciation and amortization are eliminated from the accounts and any  resulting gain or loss is reflected in current period net income (loss). Idle facilities placed on standby basis are carried at the lower of net carrying value  or estimated net realizable value. The net carrying values of idle facilities on standby are written-down to salvage value upon reaching the end of the  economic life. Therefore, with the exception of depreciation recorded on mobile equipment used in ongoing exploration and reclamation efforts at  such properties, we do not record depreciation on idle facilities when they are not in operation. Drilling and related costs of approximately $5.0 million, $3.6 million, and $3.6 million for the years ended December 31, 2012, 2011 and 2010,  respectively, met our criteria for capitalization listed above, at our properties that are in the production stage.