To provide responsive, ethical, and scientifically rigorous cultural resource management solutions that support sustainable development and protect California’s diverse heritage.

Our Mission:

About CoreStone Archaeology

CoreStone Archaeology is a certified woman-owned small business (WOSB) and a Registered Professional Archaeologist (RPA) firm, committed to upholding the highest standards in cultural resource management (CRM).​ We were founded on the idea that CRM should be both rigorous and responsive, blending scientific expertise with genuine respect for people, places, and the past. With over a decade of experience in California and the greater Southwest, we offer clients the peace of mind that comes with deep local knowledge, interdisciplinary teamwork, and a proven record of compliance with CEQA, Section 106, and local, state, and federal guidelines.

Our Story

CoreStone Archaeology was founded with a clear intention: to create a cultural resource firm that reflects the scientific integrity and human responsibility at the heart of our work. After years of leading projects across California, Katherine Sinsky saw a gap in the industry—too often, compliance was reduced to paperwork, and meaningful engagement with communities, tribes, and landscapes was treated as optional. CoreStone was created to change that.

We believe in a model where compliance isn’t a checkbox, but a stewardship process. Where collaboration, with clients, agencies, tribal nations, and communities, is central. And where environmental planning can move forward while honoring the histories, voices, and legacies tied to the land.

Our name, CoreStone, reflects this balance: the strength of a geological foundation and the idea of something central, essential, and grounding. We bring this mindset to every project, pairing deep regulatory expertise with transparency, responsiveness, and respect.

We’re proud to be a small, woman-owned business rooted in California. We’re even prouder to be building something different: a practice defined by integrity, innovation, and a genuine commitment to California’s people, landscapes, and cultural heritage.

Meet Our Founder

President & Principal Investigator: Katherine Sinsky, MA, RPA (#4668)

Katherine is a Registered Professional Archaeologist (RPA) and seasoned project manager with over a decade of professional experience in public and private sector archaeology. Her background spans data-driven fieldwork, compliance reporting, GIS, archival research, and successful collaboration with agencies, clients, and tribal partners. She has managed complex infrastructure and development projects across California, including data centers, utility corridors, transportation upgrades, affordable housing, and environmental restoration initiatives.

Katherine’s approach is grounded in stewardship, collaboration, and a commitment to scientific and ethical best practices. She has led teams of specialists and coordinated with Native American communities, agencies, and environmental consultants to deliver clear, timely results—always with an eye toward preservation and mutual respect. Her project portfolio reflects successful partnerships with the National Park Service, major utilities, environmental consulting firms, and local agencies.

What we do

We offer a full suite of cultural resource management (CRM) and archaeological services tailored for development, infrastructure, energy, and environmental projects throughout California and adjacent states.

Our core services include:

  • Archaeological Survey & Inventory
    Systematic field surveys to identify and document cultural resources in compliance with CEQA, NEPA, and Section 106 requirements.

  • Archival Research & Records Review
    Comprehensive background research to inform project planning and compliance.

  • Site Recordation & Evaluation
    Field documentation and formal significance evaluation of archaeological sites.

  • Compliance Documentation
    Preparation of reports and regulatory submissions to meet local, state, and federal requirements.

  • Native American Consultation Support
    Facilitation of meaningful communication with tribal governments and representatives, including informal outreach and correspondence as well as support under AB52 and SB18.

  • Construction Monitoring
    On-site archaeological monitoring during ground-disturbing activities to protect sensitive resources.

  • Data Recovery & Mitigation
    Planning and implementation of site mitigation strategies when avoidance is not possible.

  • GIS Mapping & Site Modeling
    Spatial analysis, mapping, and site visualization to support project planning and resource management. Analysis with detailed maps outlining locations with potential constraints and concerns for large and small project areas.

Don’t see what you need?
Please reach out with questions about custom services or teaming/subconsulting opportunities—we’d love to collaborate!

How we work

  • Seasoned in California Compliance:
    We know CEQA, Section 106, CEC, and local requirements inside and out—so your project stays on track and in line with every regulation.

  • Woman-Owned & Interdisciplinary:
    As a locally led, woman-owned business, we know that great outcomes come from diverse teams and fresh perspectives.

  • Responsive & Flexible:
    We adapt to fit your needs, offering creative solutions and clear communication every step of the way.

  • Real Collaboration:
    We prioritize genuine consultation—with tribes, agencies, and all stakeholders—because every voice matters.

  • Proven on Complex Projects:
    From multi-county infrastructure to cross-disciplinary teams, we know how to handle big, moving parts and keep everyone aligned.

  • Tech-Forward & Data-Driven:
    We use predictive modeling, GIS, and LiDAR to advance archaeological understanding and help clients make informed decisions for development, conservation, and resource management—including fuels management and wildfire resilience.