NOTE OCOMMITMENTS AND CONTINGENCIES Future Minimum Annual Commitments at June 30, 2020 (in thousands): Minimum Purchase Commitments 2020 (remaining six months) $ 3,132 2021 12,829 2022 10,328 2023 10,328 2024 7,020 Thereafter 10,147 Total future purchase commitments $ 53,784 Minimum Purchase Commitments We enter into service agreements with our transload and transportation service providers. Some of these agreements require us to purchase a minimum amount of services over a specific period of time. Any inability to meet these minimum contract requirements requires us to pay a shortfall fee, which is based on the difference between the minimum amount contracted for and the actual amount purchased. Contingent Liability on Royalty Agreement On May 17, 2017, we purchased reserves in Crane County, Texas, for $94.4 million cash consideration plus contingent consideration. The contingent consideration is a royalty that is based on the tonnage shipped to third-parties. Because the contingent consideration is dependent on future tonnage sold, the amounts of which are uncertain, it is not currently possible to estimate the fair value of these future payments. The contingent consideration will be capitalized at the time a payment is probable and reasonably estimable, and the related depletion expense will be adjusted prospectively. Other Commitments and Contingencies Our operating subsidiary, U.S. Silica Company (U.S. Silica), has been named as a defendant in various product liability claims alleging silica exposure causing silicosis. During the six months ended June 30, 2020, zero new claims were brought against U.S. Silica. As of June 30, 2020, there were 55 active silica-related product liability claims pending in which U.S. Silica is a defendant. Although the outcomes of these claims cannot be predicted with certainty, in the opinion of management, it is not reasonably possible that the ultimate resolution of these matters will have a material adverse effect on our financial position or results of operations that exceeds the accrual amounts. We have recorded estimated liabilities for these claims in other long-term liabilities as well as estimated recoveries under the indemnity agreement and an estimate of future recoveries under insurance in other assets on our consolidated balance sheets. As of both June 30, 2020 and December 31, 2019, other non-current assets included zero for insurance for third-party product liability claims. As of June 30, 2020 and December 31, 2019 other long-term liabilities included $1.0 million and $0.9 million, respectively, for third-party product liability claims. One of our subsidiaries has also been named as a defendant in lawsuits regarding certain labor practices. If we are unsuccessful in defending the litigation, these cases could result in a material liability for us. Obligations under Guarantees We have indemnified our insurers against any loss they may incur in the event that holders of surety bonds, issued on our behalf, execute the bonds. As of June 30, 2020, there was $36.4 million in bonds outstanding, of which $30.9 million relate to reclamation requirements issued by various governmental authorities. Reclamation bonds remain outstanding until the mining area is reclaimed and the authority issues a formal release. The remaining bonds relate to licenses, permits, and tax collection.