Integra Resources Announces Significant Maiden Inferred Mineral Resource Estimate at Florida Mountain

• Florida Mountain Deposit inferred mineral resource at 0.3 grams per tonne (“g/t”) gold equivalent (“AuEq”) cut-off: 36,605,000 tonnes grading 0.57 g/t gold (“Au”) and 14.12 g/t silver (“Ag”), for a total of 675,000 ozs of Au and 16.6 M ozs Ag, or 871,000 oz AuEq at a grade of 0.74 g/t AuEq

• Integra’s DeLamar Project inferred mineral resource estimate is now 3.54 M AuEq oz at a grade of 0.71 g/t AuEq using a 0.3 g/t AuEq cut-off

• Historic drill intercepts beneath current mining surface to direct upcoming exploration program, including:

• 12.83 g/t Au and 22.69 g/t Ag over 19.8 meters (“m”) (DH F125)
• 1.99 g/t Au and 97.13 g/t Ag over 45.8 m (DH FT10), including 14.05 g/t Au and 54.85 g/t Ag over 3.1 m
• 17.76 g/t Au and 50.56 g/t Ag over 6.1 m (DH F25)
  *Drill intercept lengths only are reported in the tabulations; it is estimated that true widths will be less than 75% of the reported widths

VANCOUVER, British Columbia, Feb. 08, 2018 (GLOBE NEWSWIRE) -- Integra Resources Corp. (TSXV:ITR) (OTCQB:IRRZF) (the “Company” or “Integra”) is pleased to announce that it has completed a maiden NI 43-101 resource estimate on the newly acquired Florida Mountain Gold and Silver Deposit (“Florida Mountain Deposit”, “Florida Mountain”, or the “Property”) located 8.5 km east of Integra’s DeLamar Deposit in southwestern Idaho. For the purposes of NI 43-101 reporting, Florida Mountain and DeLamar are now considered to be part of the global DeLamar Project, based on the reasonable expectation that if put into production, and as in the past, the two deposits would likely share common infrastructure.

The maiden resource estimate at Florida Mountain is defined by 840+ historical drill holes drilled to an average depth of just 130 meters, incorporating more than 108,000 meters of historic drilling. The study delineates the existing ‘open-pit’ oxide, partly oxidized and unoxidized mineralization at Florida Mountain which is hosted within felsic volcanics. The resource estimations for Florida Mountain and DeLamar were completed by Mine Development Associates (“MDA”) of Reno, Nevada.

George Salamis, President and CEO of Integra Resources, stated, “Given Florida Mountain’s 8.5 km proximity to the DeLamar Deposit, and the significant resource recently announced at DeLamar late last year, the maiden gold-silver resource at Florida Mountain provides substantial synergies for the Company as it advances its Idaho land package and expanding resource portfolio. The exploration upside at Florida Mountain is significant: below this low-grade pit-constrained resource, only two of several possible veins interpreted from available drilling were mined historically in the late 1880’s at cut-offs of more than 15 g/t Au with average grades often exceeding 30 g/t Au. Stope widths reportedly ranged from 5 meters to less than 1 meter in width. Underground workings and historic drilling demonstrate that the vein system has strike lengths in excess of 2 km and depth extensions in excess of 500 meters, extending down through the rhyolite and basalt into the underlying Idaho Granite basement.”

A sensitivity analysis of the grade and tonnage relationships at varying pit-constrained cut-off grades is shown in Table 1 below. A final 43-101 Technical Report will be filed on SEDAR within 45 days.

Table 1. Sensitivity analysis of grade and tonnage at varying pit-constrained cut-off grades on the Florida Mountain Deposit

1. Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.
2. Mineral Resources are comprised of all model blocks at a 0.3 g AuEq/t cutoff that lie within an optimized pit and below the as-mined surface
3. Gold equivalent = g Au/t + (g Ag/t ÷ 85)
4. Rounding may result in apparent discrepancies between tonnes, grade, and contained metal content.
5. The estimate of mineral resources may be materially affected by geology, environment, permitting, legal, title, taxation, sociopolitical, marketing or other relevant issues.
6. The effective date of the mineral resource estimate is January 30, 2018.

Table 2. DeLamar Project Inferred Mineral Resource at a 0.3 g/t AuEq cut-off grade

1. Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.
2. Mineral Resources are comprised of all model blocks at a 0.3 g AuEq/t cutoff that lie within an optimized pit and below the as-mined surface
3. Gold equivalent = g Au/t + (g Ag/t ÷ 85)
4. The effective date of the DeLamar area resource estimate is October 1, 2017
5. The effective date of the Florida Mountain area resource estimate is January 30, 2018.
6. The estimate of mineral resources may be materially affected by geology, environment, permitting, legal, title, taxation, sociopolitical, marketing or other relevant issues.
7. Rounding may result in apparent discrepancies between tonnes, grade, and contained metal content

Key Florida Mountain Deposit Highlights:

• Robust initial inferred mineral resource for Florida Mountain:
  • 0.3 g/t AuEq cut-off grade: 36,605,000 tonnes grading 0.57 g/t gold and 14.12 g/t silver, for a total of 675,000 oz of gold and 16,621,000 oz of silver; or 870,500 oz of AuEq averaging 0.74 g/t AuEq
  • Increasing the cut-off grade to 0.75 g/t AuEq results in the following changes to the grade and tonnes; 9,661,000 tonnes grading 1.2 g/t gold and 27.56 g/t silver, for a total of 373,000 oz of gold and 8,562,000 oz of silver, or 473,700 oz of AuEq averaging 1.52 g/t AuEq
  • Gold equivalent (AuEq) = g Au/t + (g Ag/t ÷ 85)
    
• Florida Mountain exhibits significant exploration upside, remaining open at depth and on strike, with limited historical drilling below 130 meters. The limited deep drill hole data available dating back to the early 1990’s includes multiple intercepts which have intersected a series of high-grade veins at depth, summarized in Table 3 below
  
• The gold and silver mineralized material from Florida Mountain was previously processed at the neighboring DeLamar Mill, connected to Florida Mountain via year-round haulage road. Historical mill records and column leach test studies indicate the deposit is host to excellent metallurgical gold-silver recoveries. The existing data demonstrates the potential of both conventional milling and heap leach options for any future development, subject to further studies and assessment

George Salamis, noted, “The low sulphidation epithermal system at Florida Mountain shows higher gold to silver ratios than those found at DeLamar. In terms of future potential amenability to heap leaching of this new low-grade resource, Kinross had previously conducted column leach test work on Florida mineralization which showed excellent gold and silver recoveries. The strategic advantage of having two significant resources in place at DeLamar and now Florida Mountain provides increased flexibility for Integra moving forward. The Company is in a unique position to start a drill program with an impressive resource already established at both DeLamar and Florida Mountain.”

Key Florida Mountain Resource Estimation Parameters:

• The gold and silver mineral resources at Florida Mountain were modeled and estimated by Michael Gustin of MDA, evaluating the drill data statistically, separately interpreting gold and silver mineral domains on sets of north-looking cross sections spaced at 30-meter intervals. Analysis was done on the modeled mineralization spatially and statistically to aid in the establishment of estimation and classification parameters, interpolating grades into a three-dimensional block model using the cross-sectional gold and silver mineral domains to constrain the estimation
• The reported resources have been constrained within an optimized pit shell using a gold price of USD $1,300/oz Au and a silver price of USD $18/oz Ag. These metal prices were also used to calculate gold equivalent cut-off grade and contained ounces
• Additional inputs for pit-optimization include (costs reported in USD): Mining - $2.40/tonne mined; Milling - $11.00/tonne milled; G&A - $4,000,000/yr; Tonnes per year processed – 4,375,000; Gold Recovery – 95%, Silver Recovery – 80%
• The resource estimate is based on 840+ reverse circulation holes, conventional rotary holes, and diamond core drill holes from the early 1970’s to the late 1990’s
• A technical report on the initial resource estimate will be prepared in accordance with National Instrument 43-101 – Standards of Disclosure for Mineral Projects (“NI 43-101”) and filed within 45 days of this news release on Integra’s issuer profile on SEDAR at www.sedar.com

Table 3. Highlighted Drill Intercepts Below Current Mining Surface at the Florida Mountain Deposit

*Drill intercept lengths only are reported in the tabulations; it is estimated that true widths will be less than 75% of the reported widths

To view an idealized cross section with geological and structural interpretation at Florida Mountain, please click the following link:

https://www.integraresources.com/site/assets/files/2509/fmbj_ew_cross_vfinal.pdf

History of Florida Mountain

As stated in the company’s recent NI 43-101 report authored by MDA (to view the report, please click here: (https://integraresources.com/site/assets/files/2388/43-101.pdf), historic underground mining at Florida Mountain is estimated to have produced a total of 133,000 oz of high-grade gold and 15.4 million oz of high-grade silver from 1883 to 1910 (Bonnichsen et al. undated, cited in Gierzycki 2004a). Records from these historic mining operations document that stopes were mined at cut-offs of over 15 g/t Au, many of which reported average grades in excess of 30 g/t Au.

More recent historic exploration at Florida Mountain commenced in the 1970s and continued through to 1994 when Kinross commenced open-pit mining the site. Material was mined from three areas near the crest of Florida Mountain, named the Tip Top, Stone Cabin, and Blackjack open pits, as shown in the following link: (https://www.integraresources.com/site/assets/files/2468/2018-02-09-nrm1-itr.pdf). Past mineralized material from Florida Mountain, which was mined through 1998, was hauled 8.5 kilometers and processed at the DeLamar mill. Gierzycki (2004) estimated that 124,500 oz of gold and 2.6 million oz of silver were produced from Florida Mountain through to the end of mining in 1998. In 1998, as a result of low precious metal prices, the DeLamar Project, including the Florida Mountain Mine, was placed on care and maintenance and since then the site of former open pit mining has been fully reclaimed. No drilling has been conducted on the property since 1997.

Geology and Mineralization of Florida Mountain

As a well-known low-sulphidation gold-silver epithermal system, the geology of the Florida Mountain area is generally similar to that of the DeLamar area with the important exception that the Late Cretaceous Idaho granite crops out on the flanks of Florida Mountain and was extensively penetrated by workings of the historic underground mines. Field relations demonstrate the lower basalt flows partially buried an erosional, paleo-topographic high of Silver City granite. Surface exposures and maps of the underground workings, as well as early drilling at Florida Mountain, led Lindberg (1985) to infer the granite forms a northeast-trending ridge beneath a relatively thin capping of quartz latite, tuff breccia, and one or more flows of rhyolite. As at the DeLamar area, both fissure veins and the bulk-mineable type of mineralization are present at Florida Mountain and have contributed to past gold and silver production.

Florida Mountain Metallurgy

During the 1980s, NERCO conducted column-leach and agitation-leach tests on samples of mineralized drill core from the Sullivan, Stone Cabin, and Clarke areas of Florida Mountain. The results of the column-leach tests, which were run for approximately 60 days, are summarized in Table 17.2. of the DeLamar NI 43-101 report (to view the full report, please click here: https://integraresources.com/site/assets/files/2388/43-101.pdf. As indicated in the report, gold and silver recoveries in these tests ranged from 52% to 95% for gold, and 32% to 54% for silver on crush fractions ranging from 0.25 to 2 inches, indicating potential amenability of Florida Mountain mineralization to future low-cost heap-leaching methods.

Integra plans on conducting further metallurgical test work on Florida Mountain mineralization in the future.

Qualified Person

The scientific and technical information contained in this news release has been reviewed and approved by Gary Edmondo of Reno, Nevada, who serves as Integra’s Chief Geologist, and is a "qualified person" within the meaning of National Instrument 43- 101 – Standards of Disclosure for Mineral Projects.

About Integra Resources

Integra Resources Corp. is a development-stage company engaged in the acquisition, exploration and development of mineral properties in the Americas. The primary focus of the Company is advancement of it’s DeLamar Project, consisting of the neighbouring DeLamar and Florida Mountain Gold and Silver Deposits in the heart of the historic Owyhee County mining district in south western Idaho. The first exploration program in over 25 years is currently underway on the DeLamar Project with more than 20,000 meters planned for 2018. The management team comprises the former executive team from Integra Gold Corp. The 43-101 technical report on DeLamar is available here:
https://integraresources.com/site/assets/files/2388/43-101.pdf

ON BEHALF OF THE BOARD OF DIRECTORS
George Salamis
CEO & President

CONTACT INFORMATION
Corporate Inquiries: Chris Gordon, chris@integraresources.com
Company website: www.integraresources.com
Office phone: 1 (604) 416-0576

This news release contains "forward-looking information" and "forward-looking statements" (collectively, "forward-looking statements") within the meaning of the applicable Canadian securities legislation. All statements, other than statements of historical fact, are forward-looking statements and are based on expectations, estimates and projections as at the date of this news release. Any statement that involves discussions with respect to predictions, expectations, beliefs, plans, projections, objectives, assumptions, future events or performance (often but not always using phrases such as "expects", or "does not expect", "is expected", "anticipates" or "does not anticipate", "plans", "budget", "scheduled", "forecasts", "estimates", "believes" or "intends" or variations of such words and phrases or stating that certain actions, events or results "may" or "could", "would", "might" or "will" be taken to occur or be achieved) are not statements of historical fact and may be forward-looking statements. In this news release, forward-looking statements relate, among other things, to: anticipated use of proceeds from the Private Placement; statements about the estimation of mineral resources; magnitude or quality of mineral deposits; anticipated advancement of mineral properties or programs; future operations; future exploration prospects; the completion and timing of mineral resource estimates; the length of the current market cycle and requirements for an issuer to survive in the current market cycle; future growth potential of Integra; and future development plans.

These forward-looking statements are based on reasonable assumptions and estimates of management of Integra at the time such statements were made. Actual future results may differ materially as forward-looking statements involve known and unknown risks, uncertainties and other factors which may cause the actual results, performance or achievements of Integra to materially differ from any future results, performance or achievements expressed or implied by such forward-looking statements. Such factors, among other things, include: possible variations in mineralization, grade or recovery rates; actual results of current exploration activities; actual results of reclamation activities; conclusions of future economic evaluations; business integration risks; fluctuations in general macroeconomic conditions; fluctuations in securities markets; fluctuations in spot and forward prices of gold, silver, base metals or certain other commodities; fluctuations in currency markets (such as the Canadian dollar to United States dollar exchange rate); change in national and local government, legislation, taxation, controls, regulations and political or economic developments; risks and hazards associated with the business of mineral exploration, development and mining (including environmental hazards, industrial accidents, unusual or unexpected formations pressures, cave-ins and flooding); inability to obtain adequate insurance to cover risks and hazards; the presence of laws and regulations that may impose restrictions on mining; employee relations; relationships with and claims by local communities and indigenous populations; availability of increasing costs associated with mining inputs and labour; the speculative nature of mineral exploration and development (including the risks of obtaining necessary licenses, permits and approvals from government authorities); and title to properties. Although the forward-looking statements contained in this news release are based upon what management of Integra believes, or believed at the time, to be reasonable assumptions, Integra cannot assure its shareholders that actual results will be consistent with such forward-looking statements, as there may be other factors that cause results not to be as anticipated, estimated or intended.

Readers should not place undue reliance on the forward-looking statements and information contained in this news release. Except as required by law, Integra assumes no obligation to update the forward-looking statements of beliefs, opinions, projections, or other factors, should they change, except as required by law.