Mr. Jason Kosec reports

INTEGRA ANNOUNCES MAIDEN PRELIMINARY ECONOMIC ASSESSMENT FOR WILDCAT & MOUNTAIN VIEW PROJECTS: AFTER-TAX NPV OF US$310 MILLION AND IRR OF 37%

Integra Resources Corp. has released results for the maiden preliminary economic assessment (PEA) and updated resource estimate for each of the Wildcat project and Mountain View project located in western Nevada. The PEA demonstrates the potential for a low-cost, high-margin, heap leach gold-silver operation with a phased development and production strategy, and robust economics. The average annual production of Wildcat and Mountain View, and the DeLamar project, on a combined basis is expected to exceed 200,000 ounces (oz) of gold equivalent (AuEq), demonstrating one of the largest heap leach production profiles among precious metal developers in the Great basin.

The company will host a PEA-focused webinar on Wednesday, June 28, 2023, at 8 a.m. PT (11 a.m. ET). The webinar will feature a presentation from Jason Kosec, Integra's president, chief executive officer and director, as well as a live question-and-answer session. A recording of the webinar will be available on Integra's corporate website. Register for the webinar on-line.

Wildcat and Mountain View PEA highlights:

• After-tax net present value (NPV) at a 5-per-cent discount of $309.6-million (U.S.) ($408.6-million (Canadian)) and 36.9-per-cent after-tax internal rate of return (IRR) using base-case metal prices of $1,700 (U.S.)/oz gold (Au) and $21.50 (U.S.)/oz silver (Ag).
• After-tax NPV (5-per-cent discount) of $442.1-million (U.S.) ($583.6-million (Canadian)) and 49.7-per-cent after-tax IRR using spot metal prices on June 27, 2023, of $1,920 (U.S.)/oz Au and $22 (U.S.)/oz Ag.
• Wildcat and Mountain View generate combined annual production of approximately 94,000 oz AuEq from year 1 to year 5, with average annual production of 80,000 oz AuEq over the 13 year life-of-mine (LOM).
• LOM payable metals from Wildcat and Mountain View of 1,043,000 oz AuEq.
• LOM site-level cash costs of $882 (U.S.)/oz AuEq on a co-product basis and LOM site-level all-in sustaining cash costs (AISC) of $973 (U.S.)/oz AuEq on a co-product basis.
• Year 1 initial capex (capital expenditures) of $115-million (U.S.) to begin operations at Wildcat.
• Average Au recovery of 71.4 per cent at Wildcat and 77.1 per cent at Mountain View.
• Low combined LOM strip ratio of 1.21 (Wildcat stand-alone strip ratio of 0.28).
• Total net free cash flow generated of $485-million (U.S.) over the LOM with average net annual free cash flow of $46-million (U.S.) from year 1 to year 13.
• The updated mineral resource estimate at Wildcat and Mountain View demonstrates growth of plus-23 per cent and plus-49 per cent, respectively, compared with the previous mineral resource estimates dated November, 2020:
  • 2021 to 2022 drilling at Wildcat and Mountain View allowed the company to convert the majority of the previous resource estimate from the inferred category to the indicated (measured and indicated (M&I)) category:
    • Wildcat project: 746,000 oz Au and 6,438,000 oz Ag (829,000 oz AuEq) in M&I (59,872,806 tonnes at 0.39 g/t Au and 3.34 g/t Ag), and 210,000 oz Au and 1.98 million oz (Moz) Ag (235,000 oz AuEq) in inferred (22,455,848 tonnes at 0.29 g/t Au and 2.74 g/t Ag).
    • Mountain View project: 578,000 oz Au and 3,402,000 oz Ag (622,000 oz AuEq) in M&I (28,750,517 tonnes at 0.63 g/t Au and 3.68 g/t Ag) and 60,000 oz Au and 244,000 oz Ag (63,000 oz AuEq) in inferred (4,155,502 tonnes at 0.45 g/t Au and 1.83 g/t Ag).
• The PEA results complement the 2022 prefeasibility study for the DeLamar project in southwestern Idaho, which demonstrated a base case after-tax NPV (5-per-cent discount) of $314-million (U.S.) and a 33-per-cent after-tax IRR.

Note: The company used a foreign exchange rate of $1.32 (U.S.) per $1.

Jason Kosec, Integra's president, chief executive officer and director, commented: "The updated resource estimate and PEA for Wildcat and Mountain View demonstrate two high-margin, low-cost, heap leachable gold and silver deposits with a strong combined production profile, low preproduction capex and robust economics. The PEA strengthens Integra's position in the Great basin as a multiasset developer with a pathway to become a 200,000-ounce-per-year gold-silver producer. To date, the company has successfully defined a large resource base at Wildcat and Mountain View, despite being constrained to five acres of surface disturbance. The company has submitted an exploration plan of operations for both Wildcat and Mountain View to the Bureau of Land Management which, when received, will allow for significantly increased resource expansion drilling through planned stepout drill holes. Resource growth at Wildcat and Mountain View has the potential to further enhance the economics and mine life demonstrated in the PEA results announced today."

George Salamis, executive chairman of Integra, added: "The PEA is the first major milestone following the successful merger of Integra and Millennial Precious Metals. The next major catalysts for the company includes an updated resource estimate for the DeLamar project that will incorporate gold-silver mineralized stockpile material drilled during the 2022 to 2023 winter field season, as well as the filing of the DeLamar mine plan of operations in Q4 of this year. The mine plan of operations represents a major milestone for the project and a significant step toward permitting and derisking the DeLamar project."

The PEA is preliminary in nature and includes inferred mineral resources that are too speculative geologically to have economic considerations applied to them that would enable them to be categorized as mineral reserves. There is no certainty that PEA results will be realized. Mineral resources are not mineral reserves and do not have demonstrated economic viability.

Project economics -- sensitivity to gold and silver prices

The table entitled "After-tax NPV, IRR and payback sensitivity table" illustrates a range of metal price scenarios to evaluate the after-tax economics of Wildcat and Mountain View. As shown, Wildcat and Mountain View operations remain viable in the downside commodity price scenario and also show robust economics in the upside case.

Production and cash flow profile

The PEA outlines a profitable heap leach operation with a phased development approach that sees production beginning at Wildcat and expanding to Mountain View in year 8. A phased development approach allows the company to utilize one fleet for mining and processing equipment resulting in significantly reduced total capital requirements. In total, the approximately 30,000-tonne-per-day (tpd) heap leach operation at Wildcat and 16,000 tpd heap leach operation at Mountain View is expected to process 99.5 million tonnes (Mt) of mineralized material and produce 1,043,000 oz AuEq (1,018,000 oz Au and 1,933,000 oz Ag) over the 13-year LOM.

The average annual LOM production at Wildcat and Mountain View is expected to be 80,000 oz AuEq per year, which, assuming base-case metal prices of $1,700 (U.S.)/oz Au and $21.50 (U.S.)/oz Ag, will generate total net free cash flow LOM of $485-million (U.S.) and average annual free cash flow of $46-million (U.S.) from year 1 to year 13.

Technical inputs and assumptions

Each of Wildcat and Mountain View will have its own heap leach pad and waste rock facility. The mining equipment and fleet will be moved between the two projects to provide efficient operations and value optimization. Wildcat and Mountain View will share an adsorption/desorption/recovery (ADR) plant located first at Wildcat and then moved to Mountain View in year 8, at which point the loaded carbon from production years 8 and 9 at Wildcat will be trucked to Mountain View for processing. Mining will be done using 90-tonne haul trucks, and 200-tonne and 250-tonne shovels. Material will be crushed to nine millimetres (mm) at Wildcat and 19 mm at Mountain View using a three-stage crushing circuit. No agglomeration is expected to be required at either project.

Capital and operating costs

The total site costs, including mining, processing and G&A (general and administrative) for Wildcat and Mountain View are $8.19 (U.S.)/tonne processed over the LOM. The LOM site-level cash costs net of silver byproduct for Wildcat and Mountain View are $862 (U.S.)/oz Au and $882 (U.S.)/oz AuEq on a co-product basis. The site-level AISC, which includes heap leach expansion capital for Wildcat in year 2 and Mountain View in year 9, is $956 (U.S.)/oz Au on a byproduct basis and $973 (U.S.)/oz AuEq on a co-product basis. The all-in cost (AIC) for Wildcat and Mountain View is $1,162 (U.S.)/oz Au on a byproduct basis and $1,175 (U.S.)/oz AuEq on a co-product basis, and includes Wildcat and Mountain View initial capital expenditure, heap leach expansion capital, sustaining capital, and reclamation and closure costs.

The total preproduction capex for Wildcat is estimated at $115-million (U.S.). A phased development approach results in expansion capital of $31-million (U.S.) in year 2 at Wildcat to expand the heap leach pad. In year 7, initial capital for Mountain View of $49-million (U.S.) is required for the heap leach pad and processing facility. Expansion capital of $18-million (U.S.) to increase the heap leach capacity at Mountain View is required in year 9. Other capital required throughout the LOM of $92-million (U.S.) includes financed mining equipment, sustaining capital, reclamation (net of residual value) and bonding.

Additional information

Mining

As contemplated in the PEA study, approximately 200 mining, processing, maintenance and general administrative workers are expected to be employed directly by Wildcat and Mountain View in peak years. In addition, Wildcat and Mountain View will contribute to the state and federal governments through taxation.

The PEA utilizes a phased development and mining approach with open-pit mining beginning at Wildcat and moving to Mountain View in year 8. The Wildcat project will produce over a seven-year period at a rate of approximately 30,000 tpd. Starting in year 5, prestripping as well as a mineralized material stockpiling program will commence at Mountain View. In years 7 and 8, all fixed and mobile infrastructure will move from Wildcat to Mountain View. In year 8, the majority of fixed and mobile equipment will be allocated for mining at Mountain View, in conjunction with heap leaching only at Wildcat. Mountain View will process an average of 16,000 tpd over a six-year period, followed by one year of remnant heap leaching.

The average waste to mineralization strip ratio at Wildcat is 0.28 and is 3.41 at Mountain View. The LOM strip ratio for Wildcat and Mountain View is 1.21 with approximately 220 Mt of total material moved. At Mountain View, most of the waste material is quaternary alluvium that does not require drilling or blasting. The alluviums can be moved with surface equipment and represent approximately 72 Mt of the 101 Mt of waste material at Mountain View. A cut-off grade of 0.15 g/t Au will be used at Wildcat and Mountain View.

Integra contemplates conducting open-pit mining at Wildcat and Mountain View using an owner-operated, conventional mine fleet that includes production drill rigs for mineralization definition and blasting. The operation will share mining equipment and a fleet that includes approximately 28-cubic-metre to 33-cubic-metre hydraulic shovels (200-tonne and 250-tonne shovels) and approximately 12-cubic-metre front end loaders with 90-tonne haul trucks. The company intends to optimize equipment use by moving equipment, after a rebuild program, from Wildcat to Mountain View as production declines at Wildcat and ramps up at Mountain View in years 7 and 8.

Heap leach metallurgy

The PEA includes conventional heap leaching for the processing and recovery of gold and silver. A heap leach pad will be located at both Wildcat and Mountain View, with a shared ADR plant located first at Wildcat and then moved to Mountain View. Mineralized material will be crushed to nine mm at Wildcat and 19 mm at Mountain View, using three-stage crushing, and will be placed on the pad using traditional conveyor and grasshopper stacking systems. At both projects, gold and silver will be leached using a low-concentration sodium cyanide solution and recovered using an ADR plant, to produce dore on site.

At Wildcat, 70 Mt of mineralized material will be placed on the heap leach pad. The average gold and silver recoveries are 71.4 per cent Au and 18 per cent Ag, resulting in total payable sales of 604,000 oz Au and 1.3 Moz Ag. At Mountain View, 30 Mt of mineralized material will be placed on the heap leach pad. The average gold and silver recoveries are 77.1 per cent Au and 20 per cent Ag, resulting in total payable ounces of 414,000 oz Au and 625,000 oz Ag.

Wildcat and Mountain View project resource estimates

The table entitled "Wildcat and Mountain View mineral resources" highlights the updated resource estimates for Wildcat and Mountain View that were used in the PEA study. The updated resource estimates were completed by William Lewis of Micon International Ltd.

Mineral resource

As part of the PEA, Integra completed an updated resource estimate for Wildcat and Mountain View. This resource update incorporates drilling from the 2021 to 2022 drill programs, and is based on a new geological interpretation for both the lithological and oxidation models. In addition to new drilling, which included twinning of historical drill holes, the relogging and reassaying of the available historical data provided enough information to upgrade most of the resources into the indicated category. Classification of the resources was interpreted manually, considering various information such as geology, grade and recovery continuity, as well as interpolation parameters and drilling spacing. The company utilized a general guideline of 50 m by 50 m spacing for the indicated resource and 100 m by 100 m for the inferred resource. The resources were then constrained using Lerchs-Grossmann pit optimization to respect of the definition of reasonable prospects for economic extraction. The updated resource estimate saw an increase in total in-pit AuEq ounces driven primarily by the drilling that took place in 2021 to 2022, which allowed for the reinterpretation of the oxidation profile at Wildcat and a better constraint of the high-grade breccia body at Mountain View, new geotechnical parameters and metallurgical recoveries, and a higher Au price assumption. As a result of this geological and modelling work, approximately 80 per cent of the resources for Wildcat and Mountain View are now classified as indicated.

The company utilized the resource estimate block model described above as a basis for the PEA study, however, additional modifying factors were considered for the PEA. These factors included Au prices and pit designs, among others. The modifying factors in the PEA led to a substantial difference between the mineral resource estimate and the PEA production plan.

Wildcat and Mountain View: Future opportunities and value enhancements

Through the course of conducting exploration and various studies related to the PEA work, the company has identified several prospective measures to grow the mineral resource estimate at Wildcat and Mountain View, and enhance future economics:

• Exploration upside:
  • Wildcat has significant exploration potential. To date, exploration at Wildcat has been constrained by a five-acre area of surface disturbance with regard to drill permitting. In late 2022, the company filed for an exploration plan of operations (EPO) that would increase the surface disturbance to 400 acres. This increased area of disturbance would allow the company to test drill-ready targets outside the current resource boundary.
  • In November, 2022, a surface sampling and mapping program identified several new mineralized targets outside the proposed PEA pit area at Wildcat. This increased the mineralized footprint from approximately 1.5 kilometres by 1.5 km to approximately three km by two km, and identified multiple high-priority drill-ready targets that have the potential to increase the resource at Wildcat.
• Metallurgy:
  • Through metallurgical test work completed for the PEA, the company has identified areas where further optimization could potentially increase recoveries and/or lower costs. At Wildcat, further optimizing crush size while focusing on better solution permeability has the potential to increase gold recoveries on the heap leach pad. At Mountain View, recoveries are less sensitive to crush size, suggesting the potential to decrease crushing requirements and lower costs.
• Mining upside:
  • Short haulage distances and the use of conveyor systems has helped reduce the mining costs at Wildcat and Mountain View. Additional sequencing optimization at Wildcat has the potential to further maximize in-pit dumping and provide future cost savings. Further metallurgical test work to better define the mineralized material blending requirements could also have a positive impact on the annual production profile. Studies are also under way at Wildcat to evaluate the potential of generating power on the downward conveying of material from the open pit to the heap leach pad. The potential power generated could reduce plant operating costs.

Next steps

Based on the positive results of the PEA, Integra will continue to derisk Wildcat and Mountain View through baseline and technical studies in the areas of hydrology, geotechnical and metallurgy. Once the EPO is received, the company is expected to undertake an exploration drill program to grow the resource at the Wildcat and Mountain View, which could increase the mine life and further enhance the robust economics outlined in the PEA.

The PEA was prepared by Micon International of Toronto, Canada, and included contributions from Forte Dynamics, NewFields and Convergent Mining. The PEA is preliminary in nature and includes inferred mineral resources that are too speculative geologically to have economic considerations applied to them that would enable them to be categorized as mineral reserves. There is no certainty that PEA results will be realized. Mineral resources are not mineral reserves and do not have demonstrated economic viability.

Qualified persons

The scientific and technical information contained in this news release has been reviewed and approved by Raphael Dutaut, PhD, PGeo, Integra's vice-president of exploration, and Tim Arnold, PE, SME, Integra's chief operating officer. Both individuals are qualified persons (QPs) as defined in National Instrument 43-101 -- Standards of Disclosure for Mineral Projects.

The scientific and technical information contained in this news release has also been verified and approved by the following qualified persons, within the meaning of NI 43-101: Richard Gowans, PEng, Micon International (metallurgy and mineral processing, environmental, permitting and social considerations); Andrew Hanson, PE, NewFields Project & Construction Management (heap leach infrastructure); Chris Jacobs, CEng, MIMMM, Micon International (economic analysis); Mr. Lewis, PGeo, Micon International (mineral resource estimation); Deepak Malhotra, director of metallurgy, Forte Dynamics (infrastructure); and Ralston Pedersen, PE, Convergent Mining LLC (mining).

About Integra Resources Corp.

Integra is one of the largest precious metals exploration and development companies in the Great basin of the Western United States. Integra is currently focused on advancing its three flagship oxide heap leach projects: the past-producing DeLamar project located in southwestern Idaho; and the Wildcat and Mountain View projects located in western Nevada. The company also holds a portfolio of highly prospective early-stage exploration projects in Idaho, Nevada and Arizona. Integra's long-term vision is to become a leading United States-focused mid-tier gold and silver producer.

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