Osisko Development Launches Fully-Funded 70,000-Meter Exploration Drilling Campaign Targeting New Discoveries at Cariboo Gold Project

On December 8, 2025, Osisko Development announced the launch of a fully-funded, 70,000-meter exploration drilling campaign at its 100%-owned Cariboo Gold Project in British Columbia. The program, which will utilize up to six drill rigs and run through the end of 2026, is designed to discover new mineralization and expand existing resources. Key targets include: - Cariboo Deep: 10,000 meters to test for depth extensions of the current deposit. - Proserpine Mountain: 20,000 meters to explore a high-priority regional target with open-pit potential. - Barkerville Mountain: Systematic drilling to target new discoveries near the existing deposit. - Other Regional Targets: 10,000 meters to test drill-ready targets along key mineralized trends.

This announcement is materially positive and represents a pivotal shift in the company's focus from de-risking and financing to growth and resource expansion. Reviewing the progression of news over the past year provides critical context:

• Early 2025 - Project Definition & De-risking: The year began with positive infill and exploration drill results (Feb 3, Sep 8, Oct 6), confirming the high-grade nature of the Cariboo project. This culminated in the April 28 release of an Optimized Feasibility Study (FS), which established robust project economics (C$943M After-Tax NPV5% at US$2,400/oz gold) and outlined a C$881M initial capital requirement. Positive ore sorting results in July further validated the processing flowsheet.

• Mid-2025 - Securing the Capital Stack: The most significant de-risking events occurred in the summer. On July 21, the company secured a US$450 million debt facility from Appian Capital. This was followed by the closing of a US$203 million private placement on August 15, anchored by a US$75 million investment from strategic investor Double Zero Capital LP. A further C$82.5 million was raised in October, including flow-through funds specifically earmarked for exploration.

• Late 2025 - Sharpening Focus: With capital secured, Osisko Development streamlined its portfolio by divesting the non-core San Antonio Gold Project on November 24, reinforcing its commitment to the flagship Cariboo project. The Q3 financial results (released Nov 10) confirmed a robust cash position of C$401.4 million as of September 30, 2025.

The December 8 announcement of a 70,000-meter drill program is the direct and logical outcome of these preceding events. Having successfully permitted and financed the project outlined in the FS, management is now executing on the "blue sky" potential. The program is fully funded by the recent capital raises. Its success could materially increase the project's value by expanding the resource base, extending the potential mine life, and demonstrating the district-scale nature of the Cariboo gold camp. For the market, this is a clear signal that the company has transitioned from a financing story to an execution and growth story.

Osisko Development Corp. is a Canadian-based gold development company focused on becoming an intermediate producer. Its flagship asset is the 100%-owned Cariboo Gold Project, a fully permitted, construction-ready underground gold mine in central British Columbia. The 2025 Feasibility Study outlines a 10-year mine life with average annual production of approximately 190,000 ounces of gold. The project is situated in a historic mining camp and is considered to have significant district-scale exploration potential. The property is subject to a 5% Net Smelter Return (NSR) royalty.