Mineral Resource and Reserve Estimate

The PFS also allows for the categorization of approximately 80% of the gold ounces and 73% of the tons within the NI 43-101 measured and indicated resource at Relief Canyon as proven and probable reserves (Table 3). This conversion percentage from resource to reserve highlights the quality and quantity of work in 2016 to upgrade the Relief Canyon deposit.  To date more than 1,100 holes and approximately 500,000 feet of drilling have been completed at Relief Canyon.  This includes 430 core holes and nearly 290,000 feet of drilling completed by Pershing Gold.

Table 3: 2017 Relief Canyon Oxide Reserve

Classification Cutoff Tons Gold Grade Total Gold
(opt Au) 000's (opt) (gpt) (Ounces)
Proven 0.005 13,095,400 0.024 0.822 308,500
Probable 0.005 17,434,300 0.019 0.651 326,500

Proven & Probable
30,529,700 0.021 0.719 634,900

This PFS has calculated Proven and Probable reserves for the deposit based on the estimated resources that have an effective date of November 1, 2016. A designed PFS three-phase pit contains the Measured and Indicated material shown in Table 3, which constitute the reserves for the property using a gold price of $1,250 per ounce, a cutoff grade of 0.005 ounces per ton ("opt") Au, and the detailed mine economics outlined in the PFS. In addition, a silver reserve grade can be reported for a portion of the deposit shown in Table 4 below.

Table 4: 2017 Relief Canyon Reserve with Silver Grade

Classification Tons Silver Grade Total Silver
000's (opt) (gpt) (Ounces)
Proven 4,123,900 0.095 3.253 391,300
Probable 10,268,600 0.121 4.144 1,241,300

Proven & Probable 14,392,500 0.113 3.87 1,632,600

The Mineral Reserves have an effective date of May 26, 2017. The Proven and Probable reserves are contained in the designed PFS final pit and include only oxide materials. The Measured and Indicated oxide resources are inclusive of the estimated PFS reserves.

Table 5: 2016 Relief Canyon Gold Resource

Classification Cutoff Tons Gold Grade Total Gold
(opt Au) (opt) (gpt) (Ounces)
Measured-Oxide 0.005 14,232,000 0.022 0.753 312,000
Measured-Mixed 0.010 259,000 0.058 1.990 15,000
Measured-Total variable 14,491,000 0.023 0.788 327,000

Indicated-Oxide 0.005 26,854,000 0.016 0.548 439,000
Indicated-Mixed 0.010 162,000 0.033 1.130 5,000
Indicated-Sulfide 0.020 369,000 0.050 1.712 18,000
Indicated-Total variable 27,385,000 0.017 0.582 462,000

Meas. + Ind Total variable 41,876,000 0.019 0.651 789,000

Inferred-Oxide 0.005 5,238,000 0.009 0.308 45,000
Inferred-Mixed 0.010 4,000 0.018 0.616 100
Inferred-Sulfide 0.020 4,000 0.028 0.959 100
Inferred-Total variable 5,246,000 0.009 0.308 45,200

* Mineral resources that are not mineral reserves do not have demonstrated economic viability.


The mineral resources at Relief Canyon were modeled and estimated by evaluating the drill data statistically, utilizing the geologic interpretations provided by Pershing Gold to interpret mineral domains on cross sections spaced at 50-foot intervals, rectifying the mineral-domain interpretations on long sections spaced at 10-foot intervals, analyzing the modeled mineralization geostatistically to establish estimation parameters, and estimating grades into a three-dimensional block model.

The Relief Canyon gold mineral resource is listed in Table 5 using a cutoff grade of 0.005 opt Au for oxide material, 0.01 opt Au for mixed material, and 0.02 opt Au for sulfide material. The oxide and mixed cutoffs were chosen to capture mineralization potentially available to open-pit extraction and heap-leach processing, with the higher cutoff for mixed material reflecting the expected reduction in recovered gold. The sulfide cut-off was chosen to reflect the potentially higher costs associated with sulfide processing. The effective date of the mineral resources estimate is November 1, 2016, and these Measured and Indicated resources are inclusive of the estimated PFS reserves.

Table 6: 2016 Relief Canyon Silver Resource

Classification Tons Silver Grade Total Silver
(opt) (gpt) (Ounces)
Measured-Oxide 10,550,000 0.119 4.075 1,260,000
Measured-Mixed 259,000 0.251 8.600 65,000
Measured-Total 10,809,000 0.123 4.212 1,325,000

Indicated-Oxide 6,236,000 0.094 3.219 584,000
Indicated-Mixed 162,000 0.206 7.055 33,000
Indicated-Sulfide 369,000 0.313 10.720 115,000
Indicated-Total 6,767,000 0.108 3.700 732,000

Meas. + Ind Total 17,576,000 0.117 4.007 2,057,000

Inferred-Oxide 781,000 0.066 2.260 52,000
Inferred-Mixed 4,000 0.125 4.281 1,000
Inferred-Sulfide 4,000 0.164 5.616 1,000
Inferred-Total 789,000 0.068 2.323 54,000