Harold Kl Castle Foundation

KAILUA, HI EIN: 99-6005445 Website

The Harold K.L. Castle Foundation is one of the largest private foundations headquartered in Hawaii. Established in 1962 by Harold Kainalu Long Castle, owner of Kaneohe Ranch and descendant of one of Hawaii's early missionary families, the foundation works to build resources for Hawaii's future through strategic grantmaking, convening power, and the introduction of new ideas and approaches to address pressing problems in the state.

Financial Overview

From 2024 IRS Form 990-PF · View filing

Total Assets

$171.3M

-1.3% YoY

Annual Giving

$6.9M

-8.0% YoY

Grant Count

106

-4.5% YoY

Avg Grant Size

$65K

-3.7% YoY

Under IRS private-foundation payout rules, Harold Kl Castle Foundation reported a distributable amount of $9.5M for 2024 — the minimum it must pay out in qualifying distributions.

Research compiled by Grantable AI from public sources. Last updated April 2026.

Mission & Focus Areas

The foundation's 2025 mission and strategies focus on five key areas:

Public Education Redesign & Enhancement — Close the achievement gap in public education so that all of Hawaii's children and young adults, regardless of socioeconomic background, have access to and benefit from high-quality education from prekindergarten through college that prepares them for a successful future.
Nearshore Marine Resource Conservation — Restore Hawaii's nearshore ocean areas so that current and future generations can benefit and learn from this rich natural resource.
Strengthening Ko'olau O'ahu Communities — Build on the strengths of Ko'olau O'ahu communities through support of the region's rich cultural legacy, its people, and its natural resources.
Climate Resiliency — Strengthen communities' ability to adapt to the effects of climate change.
Other Compelling Opportunities — Support a limited number of unforeseen but compelling opportunities to make a significant difference in Hawaii's future.

The foundation views grants as investments in ambitious, creative initiatives that deliver measurable results and clearly make Hawaii a better place for its children, communities, and environment.

Grantmaking

Grant Range

$150,000 to $700,000

Average Grant

$110,000

How to Apply

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Geographic Focus

Where this funder awards grants

The foundation focuses exclusively on Hawaii, with particular priority on O'ahu and especially Windward O'ahu. Since 2000, the foundation has granted more than $60 million, with over $50 million directed to organizations serving Windward O'ahu.

Grant Distribution by State

Hawaii $14.9M (90%)

District of Columbia $1.1M (7%)

Virginia $300K (2%)

California $175K (1%)

Arizona $87K (1%)

Maryland $10K (0%)

+1 more states

States

Arizona California Colorado District of Columbia Hawaii Massachusetts Maryland New York Virginia

Cities

AieaArlingtonBaltimoreBerkeleyBostonBoulderCaptain CookCharlottesvilleEwa BeachGlenmontHanaHauulaHiloHonoluluHoolehuaKaaawaKahukuKahuluiKailuaKailua Kona

Financial History

Multi-year comparison from IRS filings

Assets:

$173.5 million (2024)
$173 million (2023)
$171.3 million (2024)

Annual Revenue & Expenses:

Total revenues: $8,283,293 (2024)
Total expenses: $10,627,064 (2024)
Annual revenue: $5.3 million (alternate source)

Staffing:

7 employees (2024)
6 employees (alternate source)

Revenue

Expenses

Qualifying Distributions

Net Investment Income

Metric	2024	2023	2022
Total Assets	$171,295,453	$173,491,448	$173,044,264
Revenue	$8,283,293	$11,327,617	$8,125,647
Expenses	$10,627,064	$10,879,744	$11,246,442
Qualifying Distributions	$8,758,237	$9,503,881	$9,746,584
Net Investment Income	$7,046,551	$10,105,204	$6,568,148
Distributable Amount	$9,515,391	$8,920,185	$9,315,597

Giving Over Time

Total grant dollars and number of grants per year

Grant Insights

How this funder distributes its grants

Top Recipients

Top 10 recipients in 2024

Grant Size Distribution

250 grants across all recorded years

Open Grants

5 open opportunities from Harold Kl Castle Foundation

Show all 5 →

Foundation

Ko'olau Pilina Fund Grant

HAROLD KL CASTLE FOUNDATION

Amount

US $3,000 - US $15,000

Deadline

Rolling / Open

Foundation

Nearshore Marine Resource Conservation Grant

HAROLD KL CASTLE FOUNDATION

Amount

US $100 - US $4,000,000

Deadline

Rolling / Open

Foundation

Post-Secondary Transition RFP

HAROLD KL CASTLE FOUNDATION

Amount

Varies

Deadline

Rolling / Open

Giving History

Grant recipients and amounts by year

Among its reported 2024 grants, the largest include Hawaii Community Foundation (hcf) ($500,000), Hawaii Community Foundation (hcf) ($400,000), Hawaii Hospital Education and Research Foundation (hherf) ($150,000).

Recipient	Purpose	Amount
50CAN WASHINGTON, DC	CORE ORGANIZATIONAL SUPPORT FOR HAWAIIKIDSCAN, AN EDUCATION ADVOCACY ORGANIZATION COMMITTED TO ENSURE THAT HAWAII HAS AN EXCELLENT AND EQUITABLE EDUCATION SYSTEM [5898; PC]	$67,500
AFTER-SCHOOL ALL-STARS HAWAII HONOLULU, HI	TO MATCH AN EMPLOYEE CONTRIBUTION [6355; PC]	$500
BOTTLES4COLLEGE HAUULA, HI	WYLF YOUTH GRANT: BOTTLES4COLLEGE [5956; PC]	$5,000
BOYS & GIRLS CLUB OF HAWAII HONOLULU, HI	FOR AN UNSOLICITED GRANT AWARD TO WINDWARD BOYS AND GIRLS CLUBHOUSE [6130; PC]	$5,000
BOYS & GIRLS CLUB OF HAWAII HONOLULU, HI	OWN YOUR OWN FUTURE INITIATIVE: WHATS NEXT INITIATIVE PARENT ENGAGEMENT [5728; PC]	$20,000
BOYS TO MEN MENTORING NETWORK OF HAWAII INCORPORATED KAMUELA, HI	TO SUPPORT EXPANSION OF BOYS TO MEN HAWAII (BTMH) PROGRAMS ON HAWAI'I ISLAND, MAUI AND KAUAI [5938; PC]	$5,000
C&C OF HONOLULU OFFICE OF CLIMATE CHANGE SUSTAINABILITY AND RESILIENCY HONOLULU, HI	TO HELP THE HONOLULU CITY & COUNTY OPTIMIZE ITS CLIMATE ADAPTATION WORK ALIGNED WITH THE FOUNDATION'S NEW CLIMATE STRATEGY [5860; GOV]	$100,000
CENTER FOR TOMORROW'S LEADERS HONOLULU, HI	TO STRENGTHEN THE PERSUASIVE COMMUNICATION AND WRITING OF THE ROUGHLY 300 HIGH SCHOOL STUDENTS SERVED EACH YEAR [6368; PC]	$60,000
COLLABORATIVE SUPPORT SERVICES HONOLULU, HI	GENERAL OPERATING SUPPORT FOR THE COMMIT TO KEIKI INITIATIVE TO EDUCATE CANDIDATES AND ELECTED OFFICIALS ABOUT THE IMPORTANCE OF INVESTING IN EARLY CHILDHOOD DEVELOPMENT [6377; PC]	$50,000
COLLABORATIVE SUPPORT SERVICES HONOLULU, HI	BUILDING A COMMUNITY-BASED EARLY CHILDHOOD CONTINUUM IN THE WAIMNALO COMMUNITY OF OAHU [5605; PC]	$50,000

Leadership & Key People

Leadership team and compensation from IRS filings

Terrence George — President and Chief Executive Officer (retiring in 2025 after 22 years of service)
Alex Harris — President (as of 2025, overseeing grantmaking, strategy, and impact)
Eric Co — Chief Executive Officer (as of 2025, managing operations)
Corbett Kalama — Director
James McIntosh — Director
Beth Murph — Grants Manager

Compensation Overview

From 2024 IRS filing

From 2024 filing

Name	Title	Hours	Compensation
HENRY M D'OLIER	DIRECTOR/CHAIRMAN	2	—
DR CLAIRE L ASAM	DIRECTOR	0.5	—
DR KITTREDGE A BALDWIN	DIRECTOR	0.5	—
CORBETT AK KALAMA	DIRECTOR	0.5	—
DEE JAY A MAILER	DIRECTOR	0.5	—
JAMES H MCINTOSH	DIRECTOR	0.5	—
JENNIFER G SABAS	DIRECTOR	0.5	—
T AULANI WILHELM	DIRECTOR	0.5	—
ERIC K YEAMAN	DIRECTOR	0.5	—
CARLTON KC AU	VICE PRESIDENT OF FINANCE	8	$55,473
DENNIS ERIC CO	VICE PRESIDENT OF RESILIENCY	40	$222,888
TERRENCE R GEORGE	PRESIDENT/CEO	40	$414,566
ALEXANDER HARRIS	VICE PRESIDENT OF PROGRAMS	40	$221,541
ANN S MATSUKADO	TREASURER	40	$189,023
SUSAN L SUMIDA	SECRETARY	5	$27,799

Recent News & Activity

Recent developments and announcements

2026

Hawaii's first-ever Youth Apprenticeship in creative media launched with a $200,000 grant from the foundation (2026)

Hawai\u02BBi's first-ever Youth Apprenticeship in creative media ...

The foundation and Kamehameha Schools granted $2.1 million to Windward Community College

The Harold K.L. Castle Foundation and KS grant $2.1 million to Windward Community

The foundation is accepting grant applications through the Ko'olau Pilina Fund

Ko\u02BBolau Pilina Fund Accepting Grant Applications

2025

Leadership transition underway in 2025, moving from single CEO model to co-leadership structure with separate President and CEO roles

Contact Information

Address: 1197 Auloa Road, Kailua, HI 96734

Phone: 808-263-7073

Fax: 808-261-6918

Website: castlefoundation.org

Email: info@castlefoundation.org

Frequently Asked Questions

What does Harold Kl Castle Foundation fund?

The foundation's 2025 mission and strategies focus on five key areas: 1. **Public Education Redesign & Enhancement** — Close the achievement gap in public education so that all of Hawaii's children and young adults, regardless of socioeconomic background, have access to and benefit from high-quality education from prekindergarten through college that prepares them for a successful future. 2. **Nearshore Marine Resource Conservation** — Restore Hawaii's nearshore ocean areas so that current and …

How do I apply for a grant from Harold Kl Castle Foundation?

**Grant Amounts:** • Range: $100 to $4,000,000 • Average grant: $110,000 • Typical grant range: $150,000 to $700,000 **Annual Grantmaking:** • Approximately $7,000,000 to $7,300,000 per year • 114 grants awarded in 2023 **Application Process:** • Pre-application support is required • All prospective applicants must contact Beth Murph, Grants Manager, at 808-554-5164 before submitting an online inquiry • Decision timeline: Within 1 month for inquiry response; within 1 week after quarterly board …

Where does Harold Kl Castle Foundation make grants?

What size grants does Harold Kl Castle Foundation award?

In 2024, Harold Kl Castle Foundation awarded 106 grants totaling $6.9M — an average of about $65K per grant, based on its IRS Form 990 filings.

How much is Harold Kl Castle Foundation required to give away each year?

Private foundations must generally distribute about 5% of their assets annually. For 2024, Harold Kl Castle Foundation reported a distributable amount of $9.5M on its IRS Form 990-PF — the minimum it must pay out in qualifying distributions.