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Harold Kl Castle Foundation at a glanceAlso receives grants: funding profile →

· Private foundation

Harold Kl Castle Foundation

Its FY2024 filing reports that it accepted unsolicited grant applications.

$6.7M
Granted FY2024still arriving
106
Grants FY2024still arriving
3
States reached
$550k
Largest
01What it fundsRead
02The needRead
03Its granteesRead
04Its fieldRead
05Through PlinthRead
01What it funds
01100% classified

What it funded, over time

Every grant placed by its stated purpose and the recipient’s mission, by year, FY2020 to 2024.

Education$13MEnvironment$7.7MPhilanthropy$5.7MArts & Culture$1.9MHuman Services$1.6MCommunity Improvement$1.6MYouth Development$1.2MHealth$1.2MOther$0
02FY2024 · 106 grants

Where the money goes

Grants by size, and the largest recipients.

By grant size · FY2024

  • Under $10k20 grants · $102k
  • $10k–50k45 grants · $1.1M
  • $50k–250k35 grants · $2.9M
  • $250k+6 grants · $2.8M
$25,000
Median grant
3
States reached
$171M
Total assets
Largest grants
RecipientAmount
SOCIAL FINANCE INC$550,000
UNIVERSITY OF HAWAII FOUNDATION$529,240
KUAAINA ULU AUAMO (KUA)$500,000
HAWAII COMMUNITY FOUNDATION (HCF)$500,000
HAWAII COMMUNITY FOUNDATION (HCF)$400,000
THE NATURE CONSERVANCY OF HAWAII$280,000
UNIVERSITY OF HAWAII FOUNDATION$214,286
UNIVERSITY OF HAWAII FOUNDATION$150,000
HAWAII HOSPITAL EDUCATION AND RESEARCH FOUNDATION (HHERF)$150,000
WINDWARD SCHOOL DISTRICT$150,000
PURPLE MAIA$145,000
HAWAII CONSERVATION ALLIANCE FOUNDATION$132,715
RESOURCES LEGACY FUND$120,000
THE AMERICAN AI FORUM AKA AI EDUCATION PROJECT$115,000
COLLEGE SUMMIT INC DBA PEERFORWARD$103,163
02The need
03

Does the money reach high-need areas?

Each grant placed by the hardship in its grantee’s ZIP, against the area’s typical level.

show:

Its human-services grants (FY20–24, $1.3M) land where the poverty rate runs at 10%, against an area that typically sits at 10%. 11% of those dollars go to grantees based in above-average-need neighborhoods. Its grants skew toward lower-need ZIPs.

area typical 10%SOCIAL FINANCE INC: $150k → 16%CATHOLIC CHARITIES HAWAII: $25k → 9%LANAKILA PACIFIC: $133k → 9%PARTNERS IN CARE - OAHU'S CONTINUUM OF CARE: $75k → 9%PARTNERS IN CARE - OAHU'S CONTINUUM OF CARE: $75k → 9%LANAKILA PACIFIC: $13k → 9%LANAKILA PACIFIC: $13k → 9%NURTURE CULTIVATE INC: $10k → 9%NURTURE CULTIVATE INC: $10k → 9%AFTER-SCHOOL ALL-STARS HAWAII: $500 → 9%AFTER-SCHOOL ALL-STARS HAWAII: $500 → 9%ALTERNATIVE STRUCTURES INTERNATIONAL: $68k → 9%KUALOA-HEEIA ECUMENICAL YOUTH PROJECT (KEY): $125k → 9%KUALOA-HEEIA ECUMENICAL YOUTH PROJECT (KEY): $115k → 9%KUALOA-HEEIA ECUMENICAL YOUTH PROJECT (KEY): $110k → 9%PAEPAE O HEEIA: $100k → 9%KUALOA-HEEIA ECUMENICAL YOUTH PROJECT (KEY): $75k → 9%PAEPAE O HEEIA: $75k → 9%PAEPAE O HEEIA: $25k → 9%KUALOA-HEEIA ECUMENICAL YOUTH PROJECT (KEY): $25k → 9%KUALOA-HEEIA ECUMENICAL YOUTH PROJECT (KEY): $25k → 9%KUALOA-HEEIA ECUMENICAL YOUTH PROJECT (KEY): $10k → 9%HAWAII APPLESEED CENTER FOR LAW & ECONOMIC JUSTICE: $50k → 9%HAWAII DATA COLLABORATIVE: $20k → 9%0%20%40%50%more need →
grant to an above-average-need area below average· circle size = grant amount
How this is measured
Matched: human-services grants are those whose grantee’s IRS cause code is Human Services. Placed by people below the poverty line in the grantee’s ZIP, averaged from the tracts in that ZIP.

Which US states its grants reach

NY
MA
CA
CO
VA
MD
AZ
DC
HI
How this is measured
US grants placed by each grantee’s ZIP, which can differ from where services are delivered. Need from public data (U.S. Census/ACS, CDC PLACES, Eviction Lab, USDA), shown as context about the area, never attributed to the funder’s giving.
03Its grantees
repeat funding

Who it funds again

Organizations funded in more than one year, against those funded once.

84%of every dollar goes to organizations it has funded before.
$25M · 98 repeat orgs$4.6M to everyone else

Grantees it renews have grown median revenue +58% since the first grant, against +22% for those funded once.

98 repeat relationships: 51 still active in FY2024, 47 since wound down; 30 grantees were first funded in FY2024 (too recent to call).

How the two cohorts compare

Re-uppedFunded once

Organizations

98
78

Total granted

$25M
$2.9M

Median revenue growth · since first grant

+58%
+22%

Still filing today

66%
62%

New vs renewed · share of each year

In FY2024, 70% of grant dollars renewed an existing relationship; $1.7M went to new ones.

50%100%’20’21’22’23’24
RenewedFirst-time

Where new relationships form · theme of each grantee’s first grant

’20’21’22’23’24
EducationEnvironmentHuman ServicesArts & CultureHealthCommunity ImprovementOther
How this is measured
First-time means a grantee’s first year in the filing window; renewed means funded in an earlier year too. The renewed share climbs naturally as a portfolio matures, so the signal is a year that bucks it (a wave of new grantees). The earliest year is left-censored: relationships that predate the data read as new. Theme is the grantee’s IRS cause.

Backed again, and grew

  • UO
    UNIVERSITY OF HAWAII FOUNDATION
    5× · 2020–2024 · $7.7M · revenue +132%
  • 5I
    50CAN INC
    5× · 2020–2024 · $718k · revenue +841%
  • RL
    RESOURCES LEGACY FUND
    5× · 2020–2024 · $567k · revenue +114%

Funded once

  • HH
    HISTORIC HAWAI'I FOUNDATION
    one grant, 2023 · $175k · revenue +8%
  • KV
    KANEHUNAMOKU VOYAGING ACADEMYgraduated
    one grant, 2021 · $173k · revenue +172%
  • HC
    HAWAIIAN COMMUNITY ASSETS INCgraduated
    one grant, 2021 · $172k · revenue +93%
How this is measured

Repeat means funded in two or more distinct years. Growth and survival are read from each grantee’s own subsequent IRS filings.

04Its field

Closest unfunded matches

The nonprofits that most resemble its grantees but are not funded by it, scored along the direction from the rest of the field toward the portfolio. A resemblance in what they say they do, not a recommendation.

1
E Kupaku Ka Aina - the Hawaii Land Restoration Institute
Environment
2
Papahana Kuaola

Papahana kuaola's mission is to create quality educational programs focused on environmental restoration and economic sustainability fully integrated with hawaiian knowledge in order to exemplify a lifestyle respectful of kanaka, `aina,…

Environment
3
Hawaii Education Institute
—
4
Hawaii - American Nurses Association Foundation
Environment
5
Hui Aloha Kiholo

Our mission is to protect, perpetuate, and enhance the cultural and natural landscape of the kiholo bay area through collaborative management and active community stewardship.

Arts & Culture
6
Huliauapaa

Growing hawaii's communities through culturally based forms of innovative learning, leadership development, and collaborative networking in wahi kupuna stewardship.

Environment
7
Hui Malama I Ke Ala Ulili

To re-establish the systems that sustain our community through educational initiatives and land-based practices that cultivate abundance, regenerate responsibilities, and promote collective health and well being.

Community Improvement
8
Malama Kua Aina
Environment
9
The Haiku Aina Permaculture Initiative
—
10
Hoomahua Foundation

To support education primarily in the Waianae community on the island of Oahu. Support may included, but not be limited to, professional development, student support services, and community engagement. As educators on the Waianae coast,…

Education
11
The Kohala Center

The kohala center is an independent community-based center for research, conservation, and education.

Environment
12
Ocean Alliance Project

Protecting and promoting the marine biodiversity of Hawai'i through coral restoration, ecological monitoring, regenerative tourism, and cultural integration

Science & Tech
How this is measured
The grantee most central to the portfolio’s shape is Kipahulu Ohana Inc; the most unlike its peers is Marine Applied Research and Exploration. Resemblance is measured on each organization’s own IRS 990 mission text; it reflects how work is described, not its quality or impact.
04the grantee network

131 grantees tracked through their own filings, 2017–2025.

Each grant beside the grantee’s revenue from every source, year by year.

How this is measured

Counted here: distinct organizations funded across 2017 to 2025, not grant rows in a single year, so this will not match the grant count on the cover. 131 of the 208 grantees resolved in that span have returns of their own we could reconcile.

Each grantee is resolved to its own IRS returns. Association, dated; never a causal claim.

14
Load-bearing (≥25% of a budget)
37
Early backer (in before they grew)
129/131
Grantees still filing
94/131
Grew since first funded

Where the money sits, by cause and then by grantee

THE NATURE CONSERVANCY: $1,810,000 · OtherTHE NATURE CONSERVANCYKUAAINA ULU AUAMO (KUA): $1,732,000 · OtherKUAAINA ULU AUAMO (KUA)SOCIAL FINANCE INC: $550,000 · OtherTEACH FOR AMERICA (TFA): $535,000 · Other+121 more: $9,278,643 · Other+121 moreUNIVERSITY OF HAWAII FOUNDATION: $7,690,152 · EducationUNIVERSITY OF HAWAII FOUNDATION50CAN INC: $717,500 · Education50CAN INC+16 more: $2,064,716 · Education+16 moreHAWAII COMMUNITY FOUNDATION: $5,030,000 · PhilanthropyHAWAII COMMUNITY …BOBBY BENSON CENTER: $410,000 · PhilanthropyBOBBY BENSON CENT…+2 more: $175,000 · PhilanthropyRESOURCES LEGACY FUND: $567,000 · EnvironmentHAWAII CONSERVATION ALLIANCE FOUNDATION: $532,715 · EnvironmentCONSERVATION INTERNATIONAL FOUNDATION: $300,000 · EnvironmentKANU HAWAII: $150,000 · EnvironmentELEMENTAL EXCELERATOR INC: $127,720 · EnvironmentHEALTHY CLIMATE COMMUNITIES: $100,000 · EnvironmentHAWAIIAN ISLANDS LAND TRUST: $100,000 · Environment+10 more: $400,700 · EnvironmentHOOKUAAINA: $395,176 · Arts & CulturePOLYNESIAN VOYAGING SOCIETY: $325,771 · Arts & CultureHUI MALAMA O KE KAI FOUNDATION: $184,980 · Arts & CultureHISTORIC HAWAI'I FOUNDATION: $175,000 · Arts & CultureMANOA HERITAGE CENTER FKA MANOA VALLEY CULTURAL HERITAGE FOUND: $175,000 · Arts & CultureKO OLAU FOUNDATION: $150,000 · Arts & Culture+7 more: $204,998 · Arts & CultureKUALOA-HEEIA ECUMENICAL YOUTH PROJECT: $485,000 · Human ServicesPAEPAE O HE'EIA: $200,000 · Human ServicesLANAKILA PACIFIC: $158,083 · Human ServicesSocial Finance Inc: $150,000 · Human ServicesPARTNERS IN CARE- OAHU CONTINUUM OF CARE: $150,000 · Human ServicesHO'OLA NA PUA: $100,150 · Human ServicesALTERNATIVE STRUCTURES INTERNATIONAL: $68,000 · Human ServicesTHE PEOPLE'S FUND: $50,000 · Human ServicesHAWAII APPLESEED CENTER FOR LAW AND ECONOMIC JUSTICE: $50,000 · Human Services+4 more: $66,000 · Human ServicesWAIMANALO HEALTH CENTER: $308,916 · HealthCastle Medical Center dba Adventist Health Castle: $265,000 · HealthVISION TO LEARN: $150,000 · HealthHAWAII HOSPITAL EDUCATION & RESEARCH FDN: $150,000 · HealthHAWAII HOMELESS HEALTHCARE HUI: $125,000 · HealthPROJECT VISION HAWAII: $80,000 · HealthHALE MAKUA HEALTH SERVICES: $50,000 · Health+3 more: $60,400 · Health
Other$13,905,643Education$10,472,368Philanthropy$5,615,000Environment$2,278,135Arts & Culture$1,610,925Human Services$1,477,233Health$1,189,316

Showing the 200 largest grantees by grant value.

Each grantee by its size and the funder’s share of it; top left is load-bearing

25%50%75%100%$100k$1.0M$10M$100Mgrantee revenue →↑ funder's share of their budgetUNIVERSITY OF HAWAII FOUNDATION: $7,690,152 over 5y, 1.7% of budgetHAWAII COMMUNITY FOUNDATION: $5,030,000 over 5y, 1.4% of budgetTHE NATURE CONSERVANCY: $1,810,000 over 5y, 0.0% of budget50CAN INC: $717,500 over 5y, 1.9% of budgetRESOURCES LEGACY FUND: $567,000 over 5y, 0.1% of budgetHAWAII CONSERVATION ALLIANCE FOUNDATION: $532,715 over 3y, 38% of budgetKUALOA-HEEIA ECUMENICAL YOUTH PROJECT: $485,000 over 5y, 10% of budgetBOBBY BENSON CENTER: $410,000 over 2y, 10.0% of budgetPURPLE MAIA FOUNDATION: $397,080 over 3y, 12% of budgetHOOKUAAINA: $395,176 over 3y, 21% of budgetCHAMBER OF COMMERCE OF HAWAII: $387,360 over 5y, 6.1% of budgetCENTER FOR TOMORROW'S LEADERS: $375,000 over 4y, 17% of budgetHUI O HAUULA: $345,980 over 3y, 45% of budgetCOLLEGE SUMMIT INC: $326,663 over 3y, 6.3% of budgetPOLYNESIAN VOYAGING SOCIETY: $325,771 over 4y, 5.6% of budgetWAIMANALO HEALTH CENTER: $308,916 over 3y, 1.1% of budgetHAWAII WORKFORCE PIPELINE INC: $302,461 over 4y, 93% of budgetCONSERVATION INTERNATIONAL FOUNDATION: $300,000 over 2y, 0.1% of budgetKAI LOA INC: $274,500 over 2y, 28% of budgetCastle Medical Center dba Adventist Health Castle: $265,000 over 2y, 0.1% of budgetHAWAII ALLIANCE OF NONPROFIT ORGANIZATIONS: $260,000 over 5y, 14% of budgetMALAMA HONUA PUBLIC CHARTER SCHOOL FOUNDATION: $227,375 over 5y, 23% of budgetPAEPAE O HE'EIA: $200,000 over 3y, 7.5% of budgetKAULUAKALANA: $190,000 over 3y, 25% of budgetHUI MALAMA O KE KAI FOUNDATION: $184,980 over 4y, 15% of budgetHISTORIC HAWAI'I FOUNDATION: $175,000 over 1y, 15% of budgetMANOA HERITAGE CENTER FKA MANOA VALLEY CULTURAL HERITAGE FOUND: $175,000 over 2y, 16% of budgetKANEHUNAMOKU VOYAGING ACADEMY: $173,460 over 1y, 24% of budgetHAWAIIAN COMMUNITY ASSETS INC: $171,500 over 1y, 6.7% of budgetTHE EDUCATION INCUBATOR: $170,000 over 1y, 34% of budgetHAWAII EXECUTIVE COLLABORATIVE: $165,000 over 4y, 3.2% of budgetLANAKILA PACIFIC: $158,083 over 3y, 1.3% of budgetVISION TO LEARN: $150,000 over 2y, 0.9% of budgetSocial Finance Inc: $150,000 over 1y, 0.4% of budgetKO OLAU FOUNDATION: $150,000 over 2y, 47% of budgetNEW TEACHER CENTER: $150,000 over 3y, 0.4% of budgetHAWAII HOSPITAL EDUCATION & RESEARCH FDN: $150,000 over 1y, 4.0% of budgetPARTNERS IN CARE- OAHU CONTINUUM OF CARE: $150,000 over 2y, 2.6% of budgetKANU HAWAII: $150,000 over 4y, 34% of budgetKUPU: $145,000 over 2y, 1.0% of budgetLEGAL AID SOCIETY OF HAWAII: $135,000 over 2y, 1.2% of budgetELEMENTAL EXCELERATOR INC: $127,720 over 2y, 0.3% of budgetHAWAII HOMELESS HEALTHCARE HUI: $125,000 over 2y, 3.5% of budgetCOUNCIL FOR NATIVE HAWAIIAN ADVANCEMENT: $125,000 over 3y, 0.1% of budgetIHS THE INSTITUTE FOR HUMAN SERVICES INC: $123,002 over 1y, 0.4% of budgetKAUAI ECONOMIC DEVELOPMENT BOARD: $120,000 over 3y, 4.4% of budgetTHE MEDIATION CENTER OF THE PACIFIC INC: $110,000 over 2y, 5.9% of budgetHAWAII CHAMBER OF COMMERCE FOUNDATION: $110,000 over 1y, 8.8% of budget
Grantee by grantee: a decade per organization, before and after funding

A decade per grantee: revenue shaded, grants as bars, all rows on one timeline.

  • Who funds UNIVERSITY OF HAWAII FOUNDATION ↗
  • Who funds HAWAII COMMUNITY FOUNDATION ↗
  • Who funds THE NATURE CONSERVANCY ↗
  • Who funds 50CAN INC ↗
  • Who funds RESOURCES LEGACY FUND ↗
  • Who funds HAWAII CONSERVATION ALLIANCE FOUNDATION ↗
  • Who funds KUALOA-HEEIA ECUMENICAL YOUTH PROJECT ↗
  • Who funds BOBBY BENSON CENTER ↗
  • Who funds PURPLE MAIA FOUNDATION ↗
  • Who funds HOOKUAAINA ↗
  • Who funds CHAMBER OF COMMERCE OF HAWAII ↗
  • Who funds CENTER FOR TOMORROW'S LEADERS ↗
  • Who funds HUI O HAUULA ↗
  • Who funds COLLEGE SUMMIT INC ↗
  • Who funds POLYNESIAN VOYAGING SOCIETY ↗
  • Who funds WAIMANALO HEALTH CENTER ↗
  • Who funds HAWAII WORKFORCE PIPELINE INC ↗
  • Who funds CONSERVATION INTERNATIONAL FOUNDATION ↗
  • Who funds KAI LOA INC ↗
  • Who funds Castle Medical Center dba Adventist Health Castle ↗
  • Who funds HAWAII ALLIANCE OF NONPROFIT ORGANIZATIONS ↗
  • Who funds MALAMA HONUA PUBLIC CHARTER SCHOOL FOUNDATION ↗
  • Who funds PAEPAE O HE'EIA ↗
  • Who funds KAULUAKALANA ↗
  • Who funds HUI MALAMA O KE KAI FOUNDATION ↗
  • Who funds HISTORIC HAWAI'I FOUNDATION ↗
  • Who funds MANOA HERITAGE CENTER FKA MANOA VALLEY CULTURAL HERITAGE FOUND ↗
  • Who funds KANEHUNAMOKU VOYAGING ACADEMY ↗
  • Who funds HAWAIIAN COMMUNITY ASSETS INC ↗

Co-funders

Grantmakers whose grantees overlap with this funder’s far more than size alone predicts. Closer means stronger alignment; arcs show where they also fund each other. Here they form a tightly interlocked group: most of these funders back each other's grantees too.

Atherton Family Found…Aloha United Way IncTrustees of the Estat…The Harry and Jeanett…Bank of Hawaii Charit…J Watumull FundFirst Insurance Compa…Tradewind Group Found…Kosasa FoundationCentral Pacific Bank …Kaiser Foundation Hea…Stupski Foundation
Atherton Family FoundationHI90.9× affinity45 shared granteesties to 11 of 11Hover any node to trace its alignments.Compare side by side →

Open a dossier: Atherton Family Foundation · Aloha United Way Inc · Trustees of the Estate of Bernice Pauahi Bishop Dba Kamehameha Schools · The Harry and Jeanette Weinberg Foundation Inc · Bank of Hawaii Charitable Fdn · J Watumull Fund · First Insurance Company of Hawaii Charitable Foundation · Tradewind Group Foundation · Kosasa Foundation · Central Pacific Bank Foundation · Kaiser Foundation Health Plan Inc · Stupski Foundation

How this is measured
Affinity is a Gamma-Poisson posterior co-funding rate, re-centered on the typical rate, so thin evidence shrinks toward no signal. Overlap is association, not proof of shared intent.

How much its grantees rely on government

Each dot is one organization Harold Kl Castle Foundation funds: left to right is the share of its income from government, bottom to top the share from Harold Kl Castle Foundation. Bigger dots raise more.

2024
’20’21’22’23’24’25
no gov · 00%6%25%56%100%funder's share of their income ↑0%25%50%75%100%share of the org’s income from government →median 12%
  • Social Finance Inc: 12% of income from government
no gov moneyreceives it· size = income
0get no government money at all
35report government grants on their 990 we could not trace to a source (not plotted)
0rely on government for over half their income
typical government reliance, FY20–25
How this is measured
Government income is each org’s traced federal awards (USASpending grants and contracts) plus state payments (open checkbooks) as a share of its total revenue (IRS Form 990); the self-reported government-grant line (990 line 1e) is carried for cross-check: a grantee that reports government grants we could not trace to a source is left off the chart rather than shown as receiving none. An association, not a claim that a grant caused the public funding. Coverage is precision-first, a floor rather than a census; state records exist for 9 states, so a grantee outside them shows no state figure (dimmed) rather than a false zero. Federal award amounts are obligations, which can span years, so a single-year share is indicative. 990 filings lag 12 to 24 months.
05Through Plinth

Warm introductions · Powered by PlinthPlus

How do I get to Harold Kl Castle Foundation?

Find your warmest path to Harold Kl Castle Foundation through trustees and officers whose names appear on both boards. Search for your organization and Plinth traces the shortest route it can evidence.

Each link is a name appearing on two organizations’ public IRS 990 filings, matched on that name and, where the filings support it, on location. A same-state match has geographic support, which is a second matching feature rather than confirmation that the two are one person; a cross-state one is the likeliest to be two people who share a name. Every hop shows its tier, low-confidence and distant paths are held back rather than guessed, and it is worth confirming the person before you use the introduction.

On method. Every financial figure here is read from IRS e-file XML, the funder’s own 990/990-PF, and from the multi-year returns of the 208 grantees we resolved, each linked to its source. Grantee outcomes are each organization’s own program-service reporting (Form 990, Part III), read as association with funding, never as caused by it. Low-confidence name matches are suppressed rather than guessed. How we build these →

How this is measured
Each figure carries one of six labels. Filed is what the funder reported on its return. Official is another government record about an organization, such as a federal award or a charity register, joined by name where no shared identifier exists. Resolved is an identity we worked out where the filing named a recipient without an EIN, kept only above a measured confidence threshold. Computed is arithmetic over those, like themes, portfolio clusters and co-funder strength. Context is a statistic about a place rather than about an organization, which is what the need overlay is: it describes the area a grantee’s address sits in, not where its work lands. Inferred is drawn by a model from text, like the partnerships read out of public news and organization websites. Each is labeled where it appears.

Generated from the IRS Form 990-PF e-file return for fiscal year 2024, released 2024. Filings run roughly 12 to 24 months behind; figures are dated accordingly.

Source object · view filing

Play a game based on Harold Kl Castle’s filings →

More from the funding graph

The unnamed billions
grants reported with no recipient in the public record
The regranting layer
51% of grant dollars land in the regranting layer
The DAF merry-go-round
$9.7B circulates between donor-advised funds
The endowment market
who holds foundation money, and what just moved
The camps
funders cluster by geography, not ideology
By state
where grant money is based, and what stays home