---
title: 'Sr. Estimator at Mariana Minerals'
canonical: 'https://feeny.ai/job/sr-estimator-mariana-minerals-houston-7zy9rfdxmb0y'
type: 'job'
last_seen: '2026-09-11'
---

# Sr. Estimator at Mariana Minerals

- **Company:** Mariana Minerals
- **Location:** Houston, TX
- **Employment:** full-time
- **Work type:** onsite
- **Posted:** 2026-07-31
- **Last confirmed live:** 2026-09-11
- **Apply:** https://jobs.ashbyhq.com/marianaminerals/76c24ff0-cdff-4d57-a204-f8f387830c01/application

**Skills:** RSMeans, Excel, Data analysis, Technical drawing interpretation, Cost estimation, Mining operations knowledge, Heavy industrial knowledge, Construction knowledge, EPC/EPCM project delivery models, Mining project experience

> The Senior Estimator leads cost estimation efforts for mining and mineral processing projects, developing accurate and competitive cost estimates using RSMeans and Excel. This role involves analyzing technical documentation, collaborating with engineering and project teams, and mentoring junior staff to support stra...

## Job description

## 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!

## About Mariana Minerals

## Company Overview
- **One-liner**: Mariana Minerals is a software-first, vertically integrated minerals company focused on supplying the minerals critical to modern energy, AI, and defense technologies.
- **Entity Type**: Private (Series A, $85M funding in July 2025)
- **Headquarters**: San Francisco, California, United States
- **Founded**: Not publicly available
- **Founders**: Turner Caldwell (Co-Founder & CEO)

## Core Business
- **Primary industry**: Metal Ore Mining / Critical Minerals
- **Target customers**: B2B – energy, AI, and defense supply chains (including downstream manufacturers and government entities)
- **Mission or purpose**: "Create a future of critical mineral abundance" by reimagining the global minerals supply chain with software, automation, and data-driven decision making.

## Products & Services
- **Copper One (formerly Lisbon Valley Copper Mine)**: World’s first autonomous mine, located in Utah. Produces copper using integrated automation and software control. Restarted production in April 2026.
- **Lithium One**: Lithium project (on the roadmap or early development).
- **Other mineral projects**: Graphite, Uranium, Rare Earth Metals, Cobalt, Nickel, Aluminium – at various stages (stealth or roadmap).
- **CapitalProjectOS**: Internal software platform for capital project management (mentioned in leadership bio).
- **Technology Stack**: React, dbt, TypeScript, Python, TensorFlow, PyTorch, microservices, SCADA, Autodesk, and many others – indicating a strong software engineering backbone.

## Market Standing
- **Valuation/Market Cap**: Not disclosed (private company)
- **Key Metric**: Total funding – $85M Series A (July 2025, 1 investor)
- **Notable Investors/Partners**: Lead investor not publicly disclosed (Andreessen Horowitz was pitched but not confirmed as an investor). Partners include Bot Auto, WeRide, Pronto, Atoms (based on LinkedIn mentions). Also works with UMA (Utah Mining Association).
- **Growth Signals**: Headcount grew 3,575% YoY to 107 employees (as of mid-2026). 73 active job postings. Opened the world’s first autonomous mine (Copper One) in April/May 2026, generating significant industry news and social media engagement.

## Competitive Advantages
- **Software-first approach**: The company builds automation and data systems from the ground up, rather than layering tech onto legacy mining operations. This enables fully autonomous mining.
- **Vertical integration**: They develop, own, and operate mineral projects, controlling the entire value chain from extraction to processing.
- **Deep tech stack**: Use of AI/ML (TensorFlow, PyTorch), simulation, and real-time control systems to optimize mining operations.
- **First-mover in autonomous mining**: Copper One is claimed to be the world’s first autonomous mine, giving them a significant lead in operational efficiency and safety.

## Strategic Focus
- Scale autonomous mining operations beyond copper (lithium, graphite, uranium, etc.)
- Secure domestic supply of critical minerals for U.S. energy, AI, and defense needs.
- Continue aggressive hiring across engineering, operations, and field roles.
- Expand from Utah to additional sites (Houston engineering office, potential new projects).

## Why Work Here
- **Culture principles**: "Extreme Ownership", "Engineer Out Requirements, Then Automate", "Share Your Legos" – emphasizing accountability, simplification, and collaboration.
- **Work environment**: High-growth startup with a mission-driven focus on critical infrastructure. Offices in San Francisco (HQ), Houston (Engineering), and La Sal, Utah (mine site). Hybrid/remote policy not explicitly stated, but multiple office locations suggest flexibility for field vs. office roles.
- **Notable perks**: Opportunity to work on cutting-edge autonomous systems and AI in a traditional industry. Strong engineering culture with modern tech stack (React, Python, ML). Rapid career growth due to company expansion.
- **Talent sources**: Attracts talent from Tesla, Redwood Materials, Lilac, ExxonMobil, Amazon Web Services, and other tech/energy companies – indicating a high-caliber peer group.

## Sources
1. [marianaminerals.com](https://marianaminerals.com/)
2. [marianaminerals.com/careers](https://marianaminerals.com/careers)
3. [marianaminerals.com/about](https://marianaminerals.com/about)
4. [jobs.ashbyhq.com/marianaminerals](https://jobs.ashbyhq.com/marianaminerals)
5. [linkedin.com/company/mariana-minerals](https://www.linkedin.com/company/mariana-minerals)

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