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KSM (Kerr-Sulphurets-Mitchell): RESOURCES

All disclosure of a scientific or technical nature was prepared by, or under the supervision of, William E. Threlkeld ((Licensed Registered Geologist in the Province of British Columbia and in the State of Washington), a Vice President of Seabridge. Mr. Threlkeld is a "Qualified Person" under National Instrument 43-101.

All reserve and resource estimates reported by the Corporation were calculated in accordance with the Canadian National Instrument 43-101 and the Canadian Institute of Mining and Metallurgy Classification system. These standards differ significantly from the requirements of the U.S. Securities and Exchange Commission. Mineral resources which are not mineral reserves do not have demonstrated economic viability.

A breakdown of resources by project and resource category is available at Reserves/Resources.

2018 Updated Resource Estimate

An updated independent mineral resource estimate for the Iron Cap deposit was announced February 9th, 2018. Iron Cap is one of four large gold/copper porphyry deposits within Seabridge’s 100%-owned KSM Project located in northwestern British Columbia. The updated resource estimate, dated as at February 9, 2018, incorporates all previous drilling plus 10,383 meters of diamond core drilling completed in 11 holes drilled in 2017. All 11 holes returned wide zones of significant grade.

A comparison of the previous Iron Cap resource estimate to the updated resource estimate is as follows:

Note: Mineral Resources which are not Mineral Reserves do not have demonstrated economic viability. Drill spacing in the 2017 program was designed to meet two objectives: expand the known size of the Iron Cap deposit while also meeting the requirements of an inferred resource estimate. Based on the relatively consistent nature of the deposit and extensive drilling at Iron Cap, the Company believes it is reasonable to expect that the majority of Inferred Mineral Resources could be upgraded to Indicated Mineral Resources with continued exploration.

All resource estimates have been constrained by conceptual block cave shapes. The 2016 resource estimates were incorporated into the National Instrument 43-101 Technical Report on KSM announced on September 19, 2016. Drilling results from 2016 and 2017 coupled with selected re-logging of older core holes resulted in an updated geologic model for the entire Iron Cap deposit. This new interpretation placed more emphasis on steeper structurally controlled intrusions as one of the key controls to mineralization. Grade envelopes were developed for the current block model that constrained the mineralization with these structural controls, resulting in about a 10% decrease in gold grade for Indicated Mineral Resources. Updated molybdenum grade envelopes and domaining resulted in an increase in the estimated molybdenum grade, although those values contribute very little to the net smelter return ("NSR") value. Future infill drilling programs will focus on testing the higher grade, intrusive dominated north area with expectations of increasing the overall confidence in the mineralized system and beginning the process of converting Inferred Mineral Resources to Indicated Mineral Resources.

A larger, richer Iron Cap deposit is expected to take a more prominent place in KSM mine planning. Iron Cap has the potential to make a strong contribution to improved project economics thanks to its higher grade and its favorable capital and operating costs due to its location close to planned infrastructure. Although a 16 dollar NSR is thought to be the right cutoff in the current environment, substantial tonnages at much higher grades are also possible if required in the future. Furthermore, both size and grade of this deposit can likely continue to grow with further drilling.

Gold, copper, silver and molybdenum grades in the resource were estimated by Resource Modeling Inc. ("RMI") using inverse distance weighting methods. Independently designed gold, copper, silver, and molybdenum grade envelopes provided the primary constraint in the grade estimation plan. Those grade envelopes were updated using the new structural/lithologic model that has been developed for the Iron Cap deposit. A multi-pass inverse distance cubed estimation plan was developed using two steeply oriented search ellipses to select eligible composites for block grade estimation.

The grade models were validated visually and by comparisons with nearest neighbor models. The drill hole database that was used for the estimate of the Iron Cap mineral resources consisted primarily of data collected by Seabridge from 75 core drill holes totaling more than 45,000 meters of core drilling completed between 2005 and 2017. RMI reviewed the quality assurance/quality control protocols and concluded that the number and type of gold and copper standard reference materials (standards, blanks, and duplicates) were reasonable. Based on the performance of those standard reference materials, RMI believes that the Seabridge drill samples are reproducible and suitable for estimating mineral resources.

Block NSR values were calculated by Moose Mountain Technical Services using metal recovery projection formulae developed by Tetra Tech from metallurgical test work. This NSR value, stated in terms of Canadian dollars, reflects metal prices, a US$/C$ currency exchange rate of 0.80, and offsite transportation, smelting, and refining charges.

Iron Cap was treated as a potential block cave (bulk underground) mining target. The lateral and vertical continuity of the zone provides a geometric configuration that is likely to be amenable to these mining methods. Seabridge retained Golder Associates, a leading industry expert in underground mining, to undertake bulk underground mining studies for KSM. Golder used the block model prepared by RMI to establish three separate draw point elevations at an NSR shutoff value of C$16, and the conceptual cave footprints of these three elevations were extruded upward by 500 meters and then clipped against one another. Resources within the extruded shapes were tabulated for each of the three hypothetical draw point elevations using an NSR cutoff value of C$16, consistent with last year's resource statement in the Technical Report. Evaluation of the economic potential of Iron Cap was based on metal prices of US$3.00 per pound of copper, US$1300 per ounce of gold, US$20 per ounce of silver, US$9.70 per pound of molybdenum and a US$/C$ exchange rate of 0.83 together with estimated metal recoveries from metallurgical test work. These metal prices are generally in line with, or lower than, the metal prices used by major mining companies for their current resource disclosure for similar types of projects.

The 2017 drill program at Iron Cap confirmed that the grade of the deposit is increasing down dip and to the northwest. As a result, within the C$16 NSR cave shapes there exist large, higher grade zones that could be exploited to drive economics (see long section and cross section). In an effort to show the potential of these higher grade zones, the following table compares the undiluted tonnes and grades of the updated Iron Cap resource at various NSR cutoffs:

The lines highlighted in yellow in the table above represent the updated undiluted mineral resource tonnes, grade, and contained metal at C$16 cutoff within the three cave footprints. The tonnes, grade, and contained metal for the other NSR cutoffs are shown to provide a relative sense of the distribution of materials within the conceptual block cave shapes.

Resource estimates included herein were prepared by RMI under the direction of Michael Lechner, who is independent of Seabridge and a Qualified Person as defined by National Instrument 43-101. Mr. Lechner has reviewed and approved this disclosure.

Exploration activities by Seabridge at the KSM Project are conducted under the supervision of William E. Threlkeld, Registered Professional Geologist, Senior Vice President of the Company and a Qualified Person as defined by National Instrument 43-101. Mr. Threlkeld has reviewed and approved this disclosure. An ongoing and rigorous quality control/quality assurance protocol is employed in all Seabridge drilling campaigns. This program includes blank and reference standards; in addition, all copper assays exceeding 0.25% Cu are re-analyzed using ore grade analytical techniques. Random cross-check analyses are conducted at a second external laboratory on at least 10% of the drill samples. Samples are assayed at ISO and ASTM certified laboratories in Vancouver, B.C., using fire assay atomic adsorption methods for gold and ICP methods for other elements.

2017 Updated Resource Estimate

An updated independent mineral resource estimate for the Deep Kerr Deposit was release February 16, 2017. Deep Kerr is one of four large gold/copper porphyry deposits within Seabridge's 100%-owned KSM Project located in northwestern British Columbia. The new inferred resource at Deep Kerr now totals 1.92 billion tonnes grading 0.41% copper and 0.31 g/T gold (containing 19.0 million ounces of gold and 17.3 billion pounds of copper( constrained by conceptual block cave shapes.

The updated resource estimate represents an increase of 3.0 million ounces of gold and 2.1 billion pounds of copper over last year’s inferred resource estimate which was incorporated into the updated National Instrument 43-101 Technical Report on KSM announced on September 19, 2016.

The resource additions at Deep Kerr fall within a conceptual mine plan that supports cost-effective block-cave underground mining methods. The estimate has been constrained by this mining method. As the deposit grows year by year, it provides further opportunities for economic optimization including increased production rates and higher cutoff grades if needed.

Gold, copper, silver and molybdenum grades in the resource were estimated by Resource Modeling Inc. ("RMI") using inverse distance weighting methods and gold and copper grade domains that were designed within modeled structural and lithologic controls of mineralization for the Deep Kerr zone. Trend plane search strategies were defined for four distinct structural domains defining strike and dip projections for sample data. Copper and gold domains were comparable to those used in the resource model completed in March of 2016 that was also prepared by RMI. Drilling during the 2016 campaign corroborated the major controls identified in past drilling with respect to copper and gold distribution and the predictability of the resource model.

The grade models were validated visually and by comparisons with nearest neighbor models. The drill hole database that was used for the estimate of the Deep Kerr mineral resources consisted primarily of data collected by Seabridge from 77 core drill holes totaling more than 74,000 meters of core drilling completed between 2009 and 2016. RMI reviewed the quality assurance/quality control protocols and results associated with the Seabridge drilling and has concluded that the number and type of gold and copper standard reference materials (standards, blanks, and duplicates) were reasonable. Based on the performance of those standard reference materials, RMI believes that the Seabridge drill samples are reproducible and suitable for estimating mineral resources. Historical drill hole results were used in conjunction with the 77 Seabridge core holes to estimate block grades for the upper portion of the Deep Kerr resource.

Block net smelter return values ("NSR&334; values) were calculated by Moose Mountain Technical Services using metal recovery projection formulae developed by TetraTech from metallurgical test work. This NSR value, stated in terms of Canadian dollars, reflects metal prices, a US/Cdn currency exchange rate of 0.80, and offsite transportation, smelting, and refining charges.

Deep Kerr was treated as a potential block cave (bulk underground) mining target. The lateral and vertical continuity of the zone provides a geometric configuration that is likely to be amenable to these mining methods. Seabridge has retained Golder Associates, a leading industry expert in underground mining, to undertake bulk underground mining studies for Deep Kerr. Golder used the block model prepared by RMI to establish three separate draw point elevations at an NSR shutoff value of C%16, and the conceptual cave footprints of these three elevations were extruded upward 495 meters. Resources within the extruded shapes were tabulated for each of the three hypothetical draw point elevations using an NSR cutoff value of C$16, consistent with last year's resource statement in the Technical Report. Evaluation of the economic potential of Deep Kerr was based on metal prices of US$3.00 per pound of copper, US$1300 per ounce of gold, US$20 per ounce of silver, US$9.70 per pound of molybdenum together with estimated metal recoveries from metallurgical test work. These metal prices are generally in line with, or lower than, the metal prices used by major mining companies for their current resource disclosure for similar types of projects.

A comparison of the previous Deep Kerr inferred resource estimate to the updated resource estimate is as follows:


Note: Mineral Resources which are not Mineral Reserves do not have demonstrated economic viability. It is reasonably expected that the majority of Inferred Mineral Resources could be upgraded to Indicated Mineral Resources with continued exploration.

Resource estimates included herein were prepared by RMI under the direction of Michael Lechner, who is independent of Seabridge and a Qualified Person as defined by National Instrument 43-101. Mr. Lechner is a highly-regarded expert in his field and frequently undertakes independent resource estimates for major mining companies. Mr. Lechner has reviewed and approved this disclosure.Exploration activities by Seabridge at the KSM Project have been conducted under the supervision of William E. Threlkeld, Registered Professional Geologist, Senior Vice President of the Company and a Qualified Person as defined by National Instrument 43-101. An ongoing and rigorous quality control/quality assurance protocol was employed during the 2016 program including the submission of blank and certified reference standards, in addition all copper assays that exceeded 0.25% Cu were re-analyzed using ore grade analytical techniques. Cross-check analyses are conducted at a second external laboratory on at least 10% of the samples. Samples were assayed at ALS Chemex Laboratory, Vancouver, B.C., using fire assay atomic adsorption methods for gold and total digestion ICP methods for other elements.