Riverside Resources and Questcorp run expanded drone survey at La Union Project, Mexico

Riverside Resources Inc. [TSXV: RRI; OTCQB: RVSDF; FSE: 5YY0], with partner Questcorp Mining Corp. [CSE: QQQ; OTCQB: QQCMF; FSE: D910], the company has completed an expanded aeromagnetic drone survey at the La Union Project in Sonora, Mexico. The new data refines the drill targets and improves understanding of district-scale geologic structures. Together with property-wide structural mapping and the high-grade Phase 2 sampling results announced May 5, 2026, this information is being used to finalize drill targets ahead of the fully permitted summer 2026 drill program.

Drill roads and pads are being prepared this week, and arrangements with the drilling contractor are progressing rapidly. Geophysics provides greater conviction in the scale of the potential feeder structures and the robust magnetic sources at depth, supporting both the Carbonate-hosted Replacement Deposit targets and the Sediment-hosted, Carlin-like stratigraphic targets discussed below.

Highlights: Expanded drone aeromagnetic survey adds 145 flight lines (193 km) plus 55 km divided into 20 tie lines, for 248 km of total drone coverage building on the 2025 baseline dataset all done with 100m line spacing for quality definition.

Improved imaging of structures beneath post-mineral cover, including the new northwest-trending structures identified by spring 2026 field mapping as a potential ore control creates new drill targets.

Integrates structural mapping with detailed 1:1,000 geologic field mapping of target areas and district-scale 1:5,000 geologic mapping to characterize interpretations at depth that may be associated with mineralization.

An Induced Polarization (IP) geophysical survey is planned to commence shortly as a further input into Phase 2 drill targeting with planned 5 IP lines that will be done concurrent with drilling the first targets and sets up for continued drilling in Phase 2.

Drill roads and pads beginning to be built for upcoming Phase 2 drill program.

“The expanded aeromagnetic survey provides a much clearer view of the La Union Project’s structural framework at depth. Combined with the high-grade sampling results released earlier this month, we now have the data in hand to refine our Phase 2 drill targets with greater conviction,” said John-Mark Staude, President and CEO of Riverside Resources. “The program is progressing well, and our teams are preparing for the launch of drilling in the near term. We are also expanding the drill targets in areas where high-grade gold and base metals were previously mined, and where geophysics can now image potential source targets at depth.”

The survey was flown with a magnetometer suspended beneath a drone along parallel flight lines, with tie lines flown perpendicular to level the dataset. The expanded grid extends magnetic coverage across the property in all directions relative to the 2025 baseline survey, providing district-wide imaging of structural features and magnetic bodies at depth. The 2025 dataset was a key input into planning the Phase 1 drillholes; the expanded 2026 dataset will allow these structures to be traced more confidently beneath post-mineral cover and build a more complete exploration model for Union.

The aeromagnetic data is being integrated with the property-wide structural reinterpretation, surface and underground sampling, and the planned IP survey to finalize drill targets. With permits in hand, site access secured, and a drill contractor and geophysical service provider contracted, Riverside and Questcorp remain on track for drill mobilization at the La Union Project in the coming weeks.

The Union Project is located in northwestern Sonora and shows district-scale carbonate replacement deposit (CRD) mineralization. The project hosts historical mining areas and multiple exploration targets associated with gold, silver, zinc and lead mineralization within carbonates and structurally controlled settings. Riverside operates the project through its Mexican subsidiary while advancing exploration in partnership with Questcorp.

Riverside is a well-funded exploration company driven by value generation and discovery. The company has a strong balance sheet with over C$5,000,000 cash, no debt and tight share structure with a strong portfolio of gold-silver, copper, and REE assets and royalties in North America.