Update On Pre-Feasiblity Study And 2021 Exploration Plan At Delamar Project

VANCOUVER - Integra Resources Corp. reported exploration plans for 2021 at the DeLamar Project located in Owyhee County in southwest Idaho along with an update on the PFS and various trade-off studies currently being considered by the Company for the PFS in Q4 2021.

“This year will be pivotal for Integra as we continue to grow the gold-silver resource at the Project through exploration drilling while preparing to deliver a PFS in Q4 2021. The Company looks forward to following-up on its drill success at Florida Mountain and War Eagle as well as the first exploration program at Black Sheep which has the potential for a new discovery at the DeLamar Project. The winter drill program at the Project is currently underway with on drill rig on the Lucky Days target situated in the Black Sheep area and one drill rig on the Florida Mountain Deposit,” said, President and CEO George Salamis. “In anticipation of the Company’s PFS in Q4 2021, we are conducting various trade-off studies to unlock additional value at DeLamar through, among other initiatives, increased silver recoveries. The DeLamar and Florida Mountain Deposits are host to significant silver resources, in addition to gold, making the Project one of the largest undeveloped silver-gold resources in the Western United States. In the 2019 PEA, silver accounted for only 17% of the estimated project revenues as the study was optimized for gold-and-silver prices at that time. The low silver revenue relative to gold revenue was largely related to two factors: low heap leach recoveries of silver averaging 34% over life-of-mine and a smaller milling scenario of 2,000 tonnes per day which would recover on average 80% silver over life-of-mine. Given the large silver endowment at DeLamar, the Company is also reviewing alternative scenarios to increase silver recovery, including a larger milling operation designed to accommodate oxide and transitional material to be processed via agitated leach and HPGR as a pre-cursor to heap leaching. Increasing silver recoveries could have a materially positive effect on the project’s future economics.”

Several key trade-off studies are currently under-way, aimed to define the cost-benefit of higher metal recoveries, specifically silver, in future development scenarios at DeLamar. Recent metallurgical testwork since the 2019 PEA is being analyzed for opportunities to improve silver recovery. A deeper evaluation into the size sensitivity of both gold and silver recovery is underway, to be included in this year’s PFS. This includes consideration of HPGR technology in the final stage of the crushing circuit for the heap leach process and/or implementation of a larger milling and agitated leach circuit for higher grade transitional mineralization, both of which would effectively produce finer crushed material with enhanced silver recovery potential. Processing additional transitional mineralization through a mill circuit could potentially yield greater overall metal recovery, including silver, than through placement of crushed material on the leach pad.

Florida Mountain unoxidized material is processed through the existing milling scenario in the PEA. Testwork has shown that the unoxidized material from Florida Mountain is amenable to gravity concentration, followed by flotation of the gravity tails, with regrinding and agitated cyanide leaching of the flotation concentrate. Mill recoveries on this material in the PEA were 90% for gold and 80% for silver with a relatively course grind size of 212 µm. The Company is completing additional testwork on the DeLamar unoxidized mineralization which was not included in the PEA. This testwork includes various pre-cyanidation treatments options, including fine grinding and pre-aeration, and will be reevaluated with current metal prices and better defined costs.

One of two exploration drill rigs on the Project will operate at Florida Mountain through the winter months. Drilling at Florida Mountain will be dual-focused, including follow-up exploration on the high-grade shoots and structures below the existing resource and expanding the existing low-grade resource through drilling geochemical and geophysical anomalies to the east and west of the existing resource.

The Company has identified multiple high-grade gold-silver shoots at Florida Mountain. Integra’s exploration team has modeled 7 high-grade vein structures that appear similar in size and orientation to the historically productive high-grade Trade Dollar – Black Jack vein system. Most historic underground production stemmed from the Trade Dollar – Black Jack vein, while the remaining 6 veins saw limited production up until mining operations ceased with the start of World War I. The identified vein zones have an aggregate strike length of over 7,000 m. Within these vein zones are steeply dipping high-grade shoots with strike lengths of up to 200 m and down dip extensions of up to 300 m which are interpreted as having developed at structural intersections. Based on recent drill intercepts, the Company anticipates that the high-grade shoots are likely to have widths of between 1 m and 8 m.

Drilling is also planned to take place in the Florida Keys area, a large geochemical anomaly located immediately to the east of the resource that has seen limited drilling. The Florida Keys geochemical anomaly is of similar strength and size to the existing resource estimate footprint at the Florida Mountain Deposit. The Company also intends to drill in Rich Gulch, a target located in a large zone of Induced Polarization (“IP”) chargeability that was identified to the west of Florida Mountain as part of a 2020 geophysical survey. Based on limited historic drilling and the presence of historic underground workings in this area the Company sees potential for both additional low-grade and high-grade underground mineralization.

During the 2019 and 2020 drill programs at War Eagle, the Company intersected high-grade gold-silver mineralization within the volcanic unit overlying the entire area. In 2020, the Company identified a second high-grade shoot 400 m to the north of the 2019 drill holes. This second structure is interpreted over a strike length of approximately 550 m south-southeast and is largely untested. The geochemical soil anomaly that led the Company to this new structure is interpreted as being lateral leakage outward along the base of the latite flow, presumably emanating from the eastern most structure identified in the 2020 drill program.

Drilling in 2021 will continue to test these parallel structures at War Eagle. In addition, the Company plans on completing a detailed IP program to generate targets within a large geochemical anomaly to the east of the 2019 and 2020 drill holes locations.

Exploration drilling at Black Sheep is underway with one drill rig expected to operate through the winter months. The drill campaign at Black Sheep will focus on the Georgianna and Lucky Days targets. Black Sheep is host to extensive areas of sinter and opaline silica cut by high-level epithermal veining and brecciation. Due to the shallow level of erosion at Black Sheep, very limited exploration drilling completed by previous operators was shown to be too shallow to properly evaluate the potential for high-grade vein style mineralization. Two shallow drill holes have been completed at the Georgianna target to better define the structures controlling mineralization. Deeper, follow-up drill holes are planned at the Georgianna target for this year to test the productive zone at approximately 200 m below the current surface.

The Company also plans on drilling the Henrietta Ridge target in 2021. Henrietta Ridge is located between the DeLamar Deposit and the Black Sheep area. Historic drilling completed by previous operators along with geophysical surveys suggest mineralization from the DeLamar Deposit extends along a northwest corridor from the current resource through Henrietta Ridge.