Sr. Estimator

ABOUT MARIANA MINERALS Mariana Minerals is a software-first, vertically integrated minerals company on a mission to supply the critical minerals powering modern energy, AI, and defense technologies. We’re reimagining the minerals supply chain by combining deep industry expertise with advanced software, automation, and data-driven decision-making. ROLE OVERVIEW Mariana Minerals is seeking an experienced and detail-oriented Sr. Estimator to lead cost estimation efforts for mining and mineral processing projects. This role is responsible for developing accurate, competitive, and timely cost estimates that support strategic decision-making and project success. WHAT YOU’LL DO - Lead the preparation of detailed cost estimates for mining, processing, and infrastructure projects - Analyze drawings, specifications, proposals, and other documentation to prepare time, cost, materials, and labor estimate - Utilize RSMeans data and tools to develop accurate and benchmarked cost estimates - Collaborate with engineering, procurement, and project management teams to ensure accurate and comprehensive estimate - Develop and maintain cost databases, benchmarks, and estimating tools - Identify project risks and opportunities, providing mitigation strategies - Review and validate subcontractor and supplier quotes - Participate in bid reviews, value engineering, and project planning sessions - Provide ongoing cost analysis and support throughout the project lifecycle - Mentor junior estimators and contribute to continuous improvement initiatives - Support the PCM and Software Engineering teams in developing operating systems and tools to automate estimating processes WHAT YOU’LL BRING - 7+ years of experience in estimating within mining, heavy industrial, or construction environments - Strong knowledge of mining operations, materials, and equipment - Proficiency in RSMeans - Advanced skills in Excel and data analysis - Ability to interpret technical drawings and specifications - Strong analytical, organizational, and communication skills - Availability to travel 20% of the time to site or Mariana Minerals offices PREFERRED - Experience with EPC/EPCM project delivery models - Familiarity with mining projects OUR CULTURE IS BUILT ON THREE PRINCIPLES: Extreme Ownership – We take full responsibility for outcomes, relentlessly driving toward solutions. Engineer Out Requirements, then Automate – We simplify, optimize, and then automate for scale. Share Your Legos – We collaborate openly, share knowledge, and empower each other to build bigger, better solutions. Join us as we build the future of responsible mineral sourcing and supply.