Harold K.L. Castle Foundation

Quick Stats

Annual Giving: $7.3 million (2023)
Total Assets: $173.5 million (2024)
Success Rate: Not publicly disclosed (114 grants awarded in 2023)
Decision Time: Within 1 month for inquiry response; within 1 week after quarterly board meetings for final decisions
Grant Range: $100 - $4,000,000 (average: $110,000; typical: $150,000-$700,000)
Geographic Focus: Hawaii only, with priority on O'ahu and especially Windward O'ahu

Contact Details

Phone: 808-554-5164 (Beth Murph, Grants Manager - primary contact for new applicants)

Location: Kailua, HI

Pre-Application Support: Required - all prospective applicants must phone Beth Murph at 808-554-5164 before submitting an online inquiry

Overview

The Harold K.L. Castle Foundation, established in 1962 by Harold Kainalu Long Castle (owner of Kaneohe Ranch and descendant of one of Hawaii's early missionary families), is the largest private foundation headquartered in Hawaii. With assets of approximately $173.5 million and annual grantmaking of $7.3 million (2023), the foundation focuses strategically on four core areas: Public Education Redesign & Enhancement, Nearshore Marine Resource Conservation, Climate Resiliency, and Strengthening Windward O'ahu Communities. Since 2000, the foundation has granted more than $60 million, with over $50 million directed to organizations serving Windward O'ahu. The foundation is undergoing a leadership transition in 2025, with retiring President/CEO Terry George (22 years of service) being succeeded by a co-leadership model: Alex Harris as President (overseeing grantmaking, strategy, and impact) and Eric Co as CEO (managing operations and communications).

Funding Priorities

Grant Programs

Core Strategic Areas:

Public Education Redesign & Enhancement ($1.6 million/31% in 2024): Supporting pre-K through 12th grade public education to help low-income youth graduate with college credits and relevant career experiences
- Example: $147,798 to University of Hawaiʻi Foundation for direct admissions process development (2025)
- Example: $500 to After-School All-Stars Hawaiʻi (2024)
Nearshore Marine Resource Conservation ($1.3 million/25% in 2024): Creating immediate, measurable change in Hawaii's nearshore ocean ecosystems through community-based approaches
- Example: $282,715 to Hawaiʻi Conservation Alliance Foundation for Ahupuaʻa Accelerator program (2024)
Climate Resiliency ($140,000/3% in 2024): Supporting adaptation and resilience-building initiatives
- Example: $25,000 to University of Hawaiʻi Foundation Center for Resilient Neighborhoods O'ahu Hub (2024)
- Example: $25,000 to Vibrant Hawaiʻi for resilience hub network development across Windward Oʻahu (2024)
Strengthening Windward O'ahu Communities ($1.7 million/34% in 2024): Building social, human, and natural capital in communities from Kahuku to Makapuʻu

Special Programs:

Koʻolau Pilina Fund: $3,000-$15,000 grants on a rolling basis for community-led projects in the Koʻolau region (Kahuku to Makapuʻu). Managed by a committee of community members, prioritizing strong families, safe communities, farming/food security, health/wellbeing, and community education. Grounded in Hawaiian values: Pilina (connection), Pono (balance), Ola Ka ʻĀina/Ola Ke Kanaka (healthy lands/healthy people), and Aloha Koʻolau (community-led solutions).
Windward Youth Leadership Fund: Up to $5,000 grants (determined by youth volunteer hours) for youth-focused programs
Other Investments in Hawaii ($377,500/7% in 2024): Supporting additional statewide causes beyond core focus areas

Priority Areas

K-12 public education improvement, especially pathways to college and careers
Nearshore marine ecosystem health and conservation
Climate adaptation and community resilience
Windward O'ahu community development
Collaborative, partnership-based approaches
Projects with multiple funding sources (foundation prefers not to be sole funder)
Organizations that demonstrate how Castle Foundation funds play a "catalytic role" in addressing public issues

What They Don't Fund

Explicit Exclusions:

Individuals or businesses
Ongoing operating expenses (except for organizations critical to foundation strategies or new projects requiring start-up funding)
Vehicles
Computers
Endowments
Annual fund drives
Sponsorships, special events, dinners, and galas
Organizations based outside Hawaii
Projects outside Hawaii that don't benefit the state

Policy Restrictions:

Each organization limited to one active grant at a time
Projects outside the four strategic focus areas
Organizations expecting Castle Foundation to be the sole funder

Governance and Leadership

Board of Directors

H. Mitchell D'Olier, Chair
James H. McIntosh, Vice Chair
Dr. Claire L. Asam, Director
Dr. Kittredge A. Baldwin, Director
Corbett A.K. Kalama, Director
Dee Jay Mailer, Director
Jennifer Sabas, Director
ʻAulani Wilhelm, Director
Eric K. Yeaman, Director

Foundation Staff (as of July 1, 2025)

Eric Co, Chief Executive Officer (808-263-8922) - Joined foundation in 2011; previously marine program coordinator at The Nature Conservancy of Hawaiʻi and Pacific region restoration specialist for NOAA; holds MBA and MA from University of Hawaiʻi; serves as trustee for Bishop Museum and Polynesian Voyaging Society
Alex Harris, President (808-263-7072) - Joined foundation in 2013 to lead K-12 and higher education programs
Amber Datta, Program Officer (808-263-8909)
Ann Matsukado, CFO, Treasurer and Secretary (808-263-8920)
Linda Mekaru, Accounting and Office Manager (808-263-8903)
Beth Murph, Grants Manager (808-554-5164)
Maria Quidez, Program Officer (808-263-8917)

Leadership Perspectives

Retiring President/CEO Terry George (served 22 years, retiring July 1, 2025):

On environmental threats: "Hawaii's environment faces a significant number of threats, but the greatest one, I think, is apathy."
On complex problems: "Complex problems require comprehensive solutions."
On diversity and equity: "I am a privileged white male who has faced no racial or gender barriers to success in my life... Without humility of leadership and respectful, ongoing engagement with all sectors of our staff and community, it is easy for such foundations—and foundation leaders such as myself–to be blind to what's going on in this world of highly unequal opportunity, racism, and gender bias."
On Harold K.L. Castle's vision: "Mr. Castle believed that thriving communities needed parks to play in, churches to worship in, and schools to be educated in."

Application Process & Timeline

How to Apply

Step 1 - Pre-Application Consultation (Required): Call Beth Murph at 808-554-5164 to discuss your concept before submitting an online inquiry. The foundation emphasizes this consultation, particularly for capital projects.

Step 2 - Online Inquiry Form: Submit via the foundation's online portal at castlefoundation.org. Applications reviewed on a rolling basis.

First-Time Applicants:

Need organization's 501(c)(3) Tax ID number
Answer eligibility questions
If deemed a possible fit, either register to apply for a grant OR confer with program officer for further discussion

Returning Grantees:

Discuss idea with program officer first
Login to existing account to begin new application

Step 3 - Inquiry Review: Within one month, foundation will contact you to:

Request additional information
Invite a full proposal, OR
Decline to review further

Step 4 - Full Proposal Submission: If invited, submit full proposal by quarterly deadlines

Full Proposal Deadlines (2026):

February 10
May 12
August 4
November 10

Board Meeting Dates (2026):

March 11
June 10
September 3
December 10

Decision Timeline

Inquiry Response: Within 1 month of online inquiry submission
Final Decision: Within 1 week after board meeting
Possible Outcomes: Approval, conditional approval, deferred decision, or denial
Contingencies: Staff may recommend contingencies attached to grant payouts (e.g., progress reports, matching funds documentation)

Success Rates

While specific acceptance percentages are not publicly disclosed, the foundation awarded:

114 grants in 2023
102 grants in 2021
107 grants in 2020
80 grants in 2022

The foundation acknowledges that limited resources mean many worthy projects cannot be funded.

Reapplication Policy

If declined, wait one year before resubmitting the same request. Before reapplying, contact foundation staff to understand rejection rationale and review current strategic priorities.

Application Success Factors

What the Foundation Values

Strategic Alignment: Clear demonstration of how your project connects to one of the four strategic priorities. Review current priorities carefully—the foundation has shifted focus over time.
Collaborative Funding: The foundation "generally prefers not to be the only funder of a given project." Show other funding sources and partnerships.
Catalytic Role: Demonstrate how Castle Foundation funds will play a catalytic role in addressing public issues affecting Hawaii, with significant leverage of grant dollars.
Pre-Submission Consultation: Organizations that discuss their concept with program staff before investing time in a full proposal are more likely to succeed.
Community Connection: Particularly for Windward O'ahu projects, show deep community ties and understanding of local needs. The Koʻolau Pilina Fund specifically requires projects to be "community-led and specific to the unique needs of Koʻolau communities."
Partnership Approach: The foundation values broad-based partnerships and community-based approaches, especially for marine conservation work.

Grant Management Expectations

Budget Flexibility: Can move up to 20% of funds between budget lines annually without approval
Reporting: Progress reports and final expenditure reports required (must reflect actual expenditures, not encumbered expenses, especially for government agencies)
Extensions: Request no-cost extensions before project end date through Fluxx account
Unspent Funds: All remaining grant funds must be returned when project ends

Common Reasons for Rejection

Misalignment with strategic priorities
Limited resources and competing proposals
Geographic limitations (not serving Hawaii)
Requests for general operating support (rarely funded)
Seeking to be sole funder
Individual applicants or businesses
Projects in excluded categories (vehicles, computers, endowments, events, etc.)

University Overhead Rates

Grants under $500,000: 1% overhead rate
Grants $500,000 or more: 2% overhead rate

Key Takeaways for Grant Writers

Call first, apply later: The required pre-application phone consultation with Beth Murph (808-554-5164) is critical—use it to test alignment and get feedback before investing time in a proposal.
Geographic sweet spot: While the foundation funds statewide, projects serving Windward O'ahu (Kahuku to Makapuʻu) receive priority, with over $50 million directed there since 2000.
One grant at a time: Each organization can have only one active grant, so time your applications strategically and complete current projects before seeking new funding.
Show your funding team: Demonstrate other funding sources and partnerships—the foundation wants to be a catalytic funder, not the sole supporter.
Align with strategy, not just mission: The foundation has evolved its focus areas; ensure your project fits current strategic priorities (Public Education, Marine Conservation, Climate Resiliency, or Windward Communities), not just general Hawaii improvement.
Leverage community voices: For Windward O'ahu projects, consider the Koʻolau Pilina Fund ($3,000-$15,000) which uses community-led decision-making and may be a faster pathway than the main application process.
Plan for the long game: With quarterly deadlines and board meetings, allow 2-4 months from inquiry to decision. Applications are reviewed on a rolling basis, but full proposals follow a structured calendar.

References

Harold K.L. Castle Foundation Official Website - Accessed December 2025
Grantseeker FAQs - Harold K.L. Castle Foundation - Accessed December 2025
What We Fund - Harold K.L. Castle Foundation - Accessed December 2025
What We Don't Fund - Harold K.L. Castle Foundation - Accessed December 2025
Our Team - Harold K.L. Castle Foundation - Accessed December 2025
Harold K.L. Castle Foundation Announces New Leadership - Accessed December 2025
Harold K.L. Castle Foundation - GuideStar Profile - Accessed December 2025
Harold K.L. Castle Foundation - Wikipedia - Accessed December 2025
Harold K.L. Castle Foundation | Inside Philanthropy - Accessed December 2025
Harold K.L. Castle Foundation - ProPublica Nonprofit Explorer - Accessed December 2025
Koʻolau Pilina Fund - Accessed December 2025
Terry George Interview - Honolulu Star-Advertiser - Accessed December 2025
Diversity, Equity, and Inclusion at the Harold K.L. Castle Foundation - Accessed December 2025
Climate Resiliency Recent Grants - Accessed December 2025
Recent Grants: Public Education - Accessed December 2025
Recent Grants: Nearshore Marine Resource Conservation - Accessed December 2025