Underground Sampling Program At The Trixie Test Mine

MONTREAL - Osisko Development Corporation reported on the ongoing underground exploration program at the Trixie test mine, within the wider Tintic Project, located in the historic East Tintic Mining District in central Utah. Exploration and underground activities are focused around the 625 level at Trixie, over a strike length of 220 m (720 ft.) and a depth extent of 45 m (150 ft). Approximately 20% of the main Trixie area has been explored to date and additional potential for high grade gold exists along strike, at depth down dip and down plunge and along fault zones known to be fluid pathways for gold mineralization. High-grade gold results greater than 100 g/t are present throughout the entire sampled area, on all levels, including recent development. Exploration cross cuts in the T4 intersect mineralized material up to 25 m (80 ft.) wide and continuous between levels. High-grade gold mineralization similar to that of T2 is also present in this zone.

Chris Lodder, President, said, "Tintic continues to deliver high grade sampling results as our exploration efforts expand the area of mineralization in and around Trixie. As we continue to drive development to reach deeper levels of the mine beyond the main 625 level towards the end of 2023, we are very excited to test exploration potential of target areas located adjacent to historic mine workings that have previously not been tested to date. In addition to Trixie, our greater understanding of the controls on the various styles of precious and base metal mineralization opens up years of potential exploration growth and excitement for our shareholders."

Approximately 7,315 m (24,000 ft.) of surface reverse circulation (RC") drilling and 1,274 m (4,180 ft.)1,898 ft. of underground diamond (DD) drilling has been completed to date, which, together with the continuous face and back sampling results, will support the completion of an initial mineral resource estimate expected in the first quarter of 2023 (the "Trixie MRE"). The Trixie MRE is expected to encompass the T2, T4 and 75-85 mineral zones only, representing a small footprint adjacent to the 625 underground level, to support near-term underground activities. The Company continues to be impacted by industry-wide delays in assay turnaround time due to bottlenecks in the processing ability of assay labs. As a result, assay results remain pending for a portion of the RC and DD drilling.

The Company's primary focus remains on the completion of the Trixie portal and decline, which is approximately 30% complete to date and is expected to be completed to the 625 underground level by the second quarter of 2023. Once fully complete, 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 beyond the 625 underground level. The Company expects to provide an update on its 2023 exploration program plans in the first quarter of 2023.