Western Queen Underground Development Transforms Rumble Resources Gold Strategy

The Western Queen development by Rumble Resources Ltd represents a transformative shift in the company's strategic approach to unlocking value from its gold and tungsten assets. Rumble Resources Limited (ASX: RTR) has unveiled a comprehensive development update that signals a significant strategic pivot toward underground mining operations. The company has commenced an aggressive 20,000-metre diamond drilling program, signed a crucial processing partnership, and confirmed that underground mining delivers superior economics compared to the original open pit design.

The announcement reveals that 929 metres have already been completed by the first of two DDH1 Drilling rigs, with the second rig scheduled to arrive within weeks. Furthermore, the entire program is expected to wrap up by February 2026, positioning the company for a resource update in early 2026.

Key Project Metrics:

• Current Gold Resource: 3.72Mt @ 3.1g/t Au for 370,000 oz Au
• Western Queen South: 2.32Mt @ 2.66g/t Au for 198,900 oz
• Maiden Tungsten Resource: 4.31Mt @ 0.31% WO3 for 13.2Kt WO3
• High-grade tungsten portion: 1.44Mt @ 0.51% WO3 for 7.4Kt WO3

Management Commentary

"The drilling is off to a good start with two holes completed to date. Our review of the open pit compared to the underground mine plan shows the underground project has superior economics and we are now progressing the underground as our preferred scenario." – Peter Harold, Managing Director and CEO

Underground Mining Economics Drive Strategic Overhaul

The decision to pivot from open pit to underground mining represents a fundamental shift in Rumble's development strategy for the Western Queen development by Rumble Resources Ltd. This strategic change emerged from internal economic assessments that demonstrated the underground option's superior financial returns compared to the smaller pit design originally under consideration.

The underground scoping study, which encompasses both the Western Queen South and Central deposits, is advancing rapidly and scheduled for completion during the December 2025 quarter. In addition, this timeline positions Rumble to move toward development decisions in early 2026, coinciding with the expected completion of the current drilling program.

Underground vs Open Pit Advantages:

• Superior economic outcomes based on internal assessment
• Access to higher-grade ore zones at depth
• Reduced surface disturbance and environmental impact
• Potential for longer mine life through down-plunge extensions

The underground approach also aligns with the drill program's primary objective to discover high-grade, down-plunge extensions to existing deposits. Consequently, this strategy could significantly expand the current 370,000 oz gold resource and extend the project's operational lifespan.

Understanding Toll Processing Agreements

For investors new to mining operations, toll processing agreements represent a critical pathway for junior miners to access production without the massive capital expenditure of building their own processing facilities. In a toll processing arrangement, the mining company delivers raw ore to an established processing plant, paying fees based on throughput and recovery rates.

This approach offers several investor advantages:

• Reduced Capital Requirements: Eliminates the need for $50-100+ million processing plant construction
• Faster Path to Production: Processing facilities are already operational and permitted
• Shared Technical Expertise: Access to established metallurgical teams and optimised processes
• Flexible Scaling: Production can adjust to resource development without fixed infrastructure constraints

For Rumble, the toll processing route through Gylden Resources' Kirkalocka plant provides a clear development pathway that minimises upfront investment while maximising speed to market.

Comprehensive Five-Phase Drilling Campaign Targets Multiple Value Drivers

The current 20,000-metre program represents Rumble's most ambitious exploration effort at Western Queen, designed to address five distinct objectives that collectively position the project for development success. However, the Western Queen development by Rumble Resources Ltd requires comprehensive validation across multiple technical areas.

Drilling Program Objectives:

The program's multi-faceted approach demonstrates sophisticated resource development planning. The focus on down-plunge extensions specifically targets high-grade zones that typically offer the most attractive mining economics in underground operations.

Tungsten Resource Expansion Potential

The tungsten component adds significant strategic value, with the maiden resource of 4.31Mt @ 0.31% WO3 representing an early-stage estimate. Furthermore, the high-grade core of 1.44Mt @ 0.51% WO3 suggests substantial economic potential, particularly given tungsten's critical mineral status and supply chain concerns.

Strategic Processing Partnership Accelerates Development Timeline

Rumble's non-binding Memorandum of Understanding with Gylden Resources represents a significant development milestone, providing access to the established Kirkalocka processing facility within a 200km radius of Western Queen. For instance, this partnership eliminates one of the primary development hurdles for junior mining companies.

Processing Partnership Benefits:

The availability of a draft toll treating agreement indicates advanced commercial discussions, suggesting that processing terms and conditions are moving beyond preliminary negotiations toward executable arrangements.

Third-Party Processing Landscape

The Western Australian goldfields feature numerous processing facilities, but securing favourable toll treatment terms requires demonstrated ore quality, consistent supply commitments, and compatible metallurgy. However, Rumble's high gold recovery rates of +93% from prior mining operations provide strong technical validation for processing negotiations.

Investment Thesis: Multi-Commodity Resource Play with Clear Development Pathway

Rumble Resources presents a compelling investment opportunity centred on the Western Queen development by Rumble Resources Ltd's transition from exploration to development. The strategic pivot to underground mining, combined with the processing partnership and aggressive drilling program, creates multiple value catalysts for investor consideration.

Key Investment Drivers:

Economic Validation Timeline

The convergence of multiple development streams during Q4 2025 and Q1 2026 creates a concentrated period of potential value recognition. Consequently, the underground scoping study completion, combined with drilling results and processing agreement finalisation, could provide comprehensive project economics within a six-month window.

Tungsten Strategic Value

The tungsten component deserves particular investor attention given its classification as a critical mineral. Current global supply chains face concentration risks, creating potential premium pricing for Western-sourced tungsten. In addition, the 7.4Kt WO3 high-grade portion represents substantial strategic value beyond traditional gold mining metrics.

Comparative Industry Position

Within the Western Australian goldfields, projects with established resources, processing partnerships, and dual-commodity potential represent a select group. Furthermore, Rumble's combination of proven gold grades, tungsten upside, and clear development pathway positions it favourably among regional development opportunities.

Why Investors Should Track This Development Story

Rumble Resources has assembled the critical components for a successful mining development: proven resources, superior mining economics, processing partnerships, and aggressive exploration growth. The strategic shift to underground mining, validated by internal economic studies, suggests management's commitment to optimising project value rather than pursuing development at any cost.

Immediate Catalysts to Monitor:

• Drilling Results: Regular updates throughout the 20,000m program
• Scoping Study: Underground economics validation in Q4 2025
• Processing Agreement: Final toll treatment terms with Gylden
• Resource Update: Enhanced MRE expected early 2026

Longer-term Value Drivers:

• Permitting Progress: Underground mining approvals
• Production Timeline: Clear path to cash flow generation
• Tungsten Development: Strategic mineral market positioning
• Regional Exploration: District-scale tungsten potential

Investment Takeaway

Rumble Resources has positioned itself as a near-term gold producer with significant tungsten upside, leveraging superior underground economics and strategic processing partnerships. With multiple catalysts converging through early 2026, investors should monitor this development story closely as it transitions from exploration to production planning.

The combination of proven resources, strategic partnerships, and aggressive development timelines creates a compelling narrative for investors seeking exposure to Western Australian gold production with critical mineral upside. Consequently, the company's systematic approach to development de-risking through processing partnerships and comprehensive drilling programs demonstrates the strategic planning necessary for successful mining development.

Ready to Explore Rumble Resources' Underground Development Opportunity?

With Rumble Resources pivoting to superior underground mining economics at Western Queen and advancing towards production through strategic partnerships, now could be an opportune time to evaluate this dual-commodity development story. The convergence of multiple value catalysts through early 2026 – including the 20,000-metre drilling programme, underground scoping study completion, and processing agreement finalisation – positions RTR as a compelling investment consideration in the Western Australian goldfields. Discover more about Rumble Resources' development pathway and investment potential.