Initial Mineral Resource Estimate For The Trixie-Tintic Project

MONTREAL - Osisko Development Corp. reported on the initial mineral resource estimate (MRE) for the underground Trixie deposit, within the wider Tintic Project, located in East Tintic Mining District in central Utah.

Chris Lodder, President, said, "The initial Trixie MRE reflects a very limited footprint of the historically defined mineralized zones at Trixie and was delineated within only six months of the acquisition of the project. It exhibits outstanding precious metal grade potential within the structural corridors of the host quartzite and based on all data received and compiled to date we see potential to continue to extend mineralization at depth and on strike throughout and parallel to the historic mine footprint as well as repeats at several other prospects and past producers in the East Tintic District. This resource will assist the Company with its near-term exploration and operational planning."

The Trixie MRE comprises five mineralized zones within the greater Trixie deposit, including T1, T2, T3, T4 and 75-85 zones over a strike length of 610 meters ("m"), a maximum width of 105 m and to a maximum depth of 295 m. The Trixie MRE is based on 4,467 underground chip samples, 4,780.1 m of current and verified historic drilling in 50 holes, of which 3,228.9 m of drilling in 23 holes were drilled by the Company in 2022. Gold mineralization is associated with high sulphidation epithermal mineralization, structurally controlled, and hosted within the quartzites. Mineralization consists of native Au, and rare Au-Ag rich telluride minerals with quartz and quartz-barite-sulphosalt stockwork veining.

Approximately 50% of the 1,390 meter (4,550 ft.) Trixie portal underground decline ramp has been completed to date. On track to reach the 625 level by the second quarter of 2023. The decline will significantly improve access to the underground workings, expand potential underground exploration target areas and provide sufficient flexibility to complete additional programs targeting mineral resource growth potential beyond the 625 level.

Excavation of deeper underground levels is anticipated to continue in the second half of 2023 and beyond, to facilitate deployment of mechanized mining equipment and to increase the overall potential mining rate capacity of the operation currently constrained by a single shaft. Target to ramp up processing capacity to 500 short tons per day by the end of 2023.

To achieve higher operating rates, certain existing processing infrastructure at the Burgin mill will need to be upgraded and/or amended, including the construction of a new mill facility to support higher processing rates. During this time, it is anticipated that VAT leach processing and certain small scale underground test mining activities will be temporarily suspended while the Company focuses its efforts on fast tracking the mill expansion, accelerating decline development, and refurbishing existing surface and underground infrastructure in preparation for higher operating rates.

Underground activities will continue to focus on exploration development along the 625 level to the Sioux-Ajax Fault, following identified mineralized zones, and on building a stockpile of mineralized material to provide operational flexibility during the commissioning phase of the upgraded mill facility.

The Company expects to advance rehabilitation of the Trixie shaft and the 750 level to allow for further underground sampling and diamond drilling. There are currently two underground diamond drills operating on the 625 level.