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 four principles:

Everyone Gets Home Safe. We never put speed or cost ahead of people.

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!