California · Nonprofit
MARIN OPEN SPACE TRUST
MARIN OPEN SPACE TRUST (California) receives grants from 18 organizations whose IRS filings report $2,201,223 to it, the largest being FIDELITY INVESTMENTS CHARITABLE GIFT FUND ($1,043,800). 8 of them have funded it in more than one year, and 86% of the money arrives through donor-advised or pass-through sponsors rather than from an institution directly.
- Revenue FY2025
- $128k
- Funders on record
- 18
- Grants received
- $2.2M
- Net assets
- $687k
What Marin Open Space Trust does
Mission
Raise funds to acquire, restore, and protect open space and park lands in Marin County, California, and negotiate acquisitions of lands and conservation easements
As stated on its FY2025 Form 990.
Programs
Completed remaining expenses, including establishing a restoration fund, for the 100-acre Wall property open space in Fairfax, California. The property was turned over to the Town of Fairfax for ownership with Marin County Parks and Open Space assuming responsibility for trails.
$67,183 spentof which $5,500 as grants83% of program spendingEntered into a purchase and sales agreement, for purchase of a 7-acre hilltop knoll in Fairfax, California and bordering the Town of San Anselmo. The site is contiguous with adjoining open space. When transactions are completed the property would become part of the Marin County Open Space District.
$8,365 spent10% of program spendingMonitoring of three conservation easements owned by MOST along with protection work at the 135-acre San Geronimo Commons easement. Work on San Geronimo easement involved salmonid habitat enhancement and flood plain restoration.
$2,438 spent3% of program spendingMemberships with affiliated groups including the California Council of Land Trusts Land Trust Alliance and Together Bay Area.
$2,804 spent3% of program spending
The 4 programs described on its FY2025 Form 990, listed largest first by expense. Program spending in total: $80,790.
The organization over time
Each line starts at 100 in 2020, so what you read is the shape rather than the size: 150 means half as much again as 2020, 50 means half. The number beside each label in the key is where it ended. The shaded band is where the middle 50% of its peers' revenue would sit, given their growth.
Balance sheet
Total assets and total liabilities at each year end, in dollars. The largest one-year move in total assets was 2021 to 2022, from $212k to $1.2M (+479%).
How it's funded, over time
Each bar is one year's revenue split into where it came from, and every bar is the same height — these are shares, not amounts, so a year that raised twice as much looks the same size. Hover a bar for the split.
Government-grant reliance: 2020 0% · 2021 0% · 2022 0% · 2023 25% · 2024 0% · 2025 0%. Grants only. Government contracts and fees sit inside program revenue.
85% of MARIN OPEN SPACE TRUST’s revenue is contributions — about as donation-reliant as the typical peer (88% for the typical peer).
Surplus & reserves
Operating surplus or deficit each year, and months of liquidity in hand. 2 of the last 6 reported years ran a deficit.
reserve
Leadership and staff
The officers, directors, trustees and key employees listed on each return. Joined and no longer listed compare each filing with the year before, matching people by surname and first initial; a year after a gap, or a roster under three people, has no comparison.
Board chair
William Long
Chair
As listed on its FY2025 Form 990.
Who funds it, year by year
2019 → 2023: the base broadened from 1 funder to 7 funders, grant income rose $9k → $338k.
10 of 18 of your funders are donor-advised or pass-through sponsors (tagged DAF) — 86% of grant dollars received. That money is really individual donors directing a sponsor; the institutions to cultivate are the non-DAF funders.
From the IRS filings of MARIN OPEN SPACE TRUST’s funders (the co-funder graph). Association, not causation. Trends are read to FY2023, the last fiscal year that has finished arriving. FY2024–FY2026 are still being filed and are shown unshaded; they do not move any figure on this page.
How concentrated its funding is
MARIN OPEN SPACE TRUST leans on a few funders — its largest provides 47% of grant income and the top three 69%; half comes from just 2 funders.
the vertical line marks half of all grant income — 2 funders to its left
92% of the income these shares are computed over arrives through pass-through sponsors or from payers whose filings do not say what kind of payment it is. Concentration is still measured over all of it, because the money is real; what it does not support is a claim about how many institutions have chosen to fund MARIN OPEN SPACE TRUST.
Largest funder’s share by year: 2019 100% · 2020 96% · 2021 70% · 2022 57% · 2023 55% — diversifying over time.
“Effective funders” = inverse Herfindahl index (1 / Σ shareᵢ²) — the number of equal-sized funders that would give the same concentration. Trends are read to FY2023, the last fiscal year that has finished arriving. FY2024–FY2026 are still being filed and are shown unshaded; they do not move any figure on this page.
How long its funders stay
40% of MARIN OPEN SPACE TRUST's funders are still giving 3 years after their first grant; 44% give in more than one year at all.
Share of funders still giving k years after their first recorded grant, pooled across every acquisition cohort. A funder counts as retained in a year only if it made a grant that year. Measured to FY2023, the last fiscal year that has finished arriving — a funder cannot be counted as lapsed in a year most filers have not reached.
Where its funders are
86% of MARIN OPEN SPACE TRUST's grant income arrives through donor-advised or pass-through sponsors, whose addresses record where the money is held rather than where the donor is. Of the $312k that is directly attributable, 100% of it comes from California funders.
In-state vs out-of-state, by year
Funder states come from each funder’s own filing. $1.9M arriving through sponsors registered in 9 states is excluded from the map and the split above: a sponsor holds money on a donor’s behalf, so its registered address would place those dollars somewhere no donor need ever have been. Trends are read to FY2023, the last fiscal year that has finished arriving. FY2024–FY2026 are still being filed and are shown unshaded; they do not move any figure on this page.
Against its field
MARIN OPEN SPACE TRUST runs a healthier operating margin than three-quarters of the 2,433 environment nonprofits its size.
this organization peer median middle 50% of peers· 2,433 environment nonprofits $100k–$1M, FY2025
Organizations like MARIN OPEN SPACE TRUST
Organizations whose mission and program text most resemble this one, by semantic similarity over every organization in the US filings — the closest peers, and often the clearest route to shared or prospective funders.
In California
Nationally
Read directly from this organization’s own Form 990, as neutral context.
Where the money goes
93% of spending goes to programs.
Governance
Public support
97%
Share of support from the public (Schedule A) — the basis for its public-charity status.
Footprint & structure
Files a return copy in 1 state
Screen this organization
A dated, signed PDF of the compliance screen for MARIN OPEN SPACE TRUST: IRS status (Business Master File, Publication 78, auto-revocation), the OFAC sanctions lists, the Internal Revenue Bulletin, and California registration, with the Rev. Proc. 2018-32 §8.01 reliance elements stated element by element. Generated from the current files at the moment you download it.
Screens are triage, not determinations; a source that cannot be read reports not screened, never clear. Screen this nonprofit · How the screen works · on the API as GET /api/screening/{ein}?format=pdf
Questions and answers
- Who funds MARIN OPEN SPACE TRUST?
- MARIN OPEN SPACE TRUST (California) receives grants from 18 organizations whose IRS filings report $2,201,223 to it, the largest being FIDELITY INVESTMENTS CHARITABLE GIFT FUND ($1,043,800). 8 of them have funded it in more than one year, and 86% of the money arrives through donor-advised or pass-through sponsors rather than from an institution directly.
- How many funders does MARIN OPEN SPACE TRUST have?
- IRS filings report 18 organizations giving $2,201,223 in grants to MARIN OPEN SPACE TRUST, 8 of which have funded it in more than one year.
- Who is the largest funder of MARIN OPEN SPACE TRUST?
- FIDELITY INVESTMENTS CHARITABLE GIFT FUND is the largest funder on record, with $1,043,800 in grants. The full list of funders is on this page.
- How can an organization like MARIN OPEN SPACE TRUST find more funders?
- Start with the funders already giving here, then look at the foundations that back similar organizations in California. The funding by cause and by state pages list the largest funders for a given area and how to approach them.
Play a game about who funds Marin Open Space →
These figures are read directly from IRS Form 990 / 990-PF e-file XML: this organization’s own return for FY2025 (financials across 2020–2025), and the filings of 18 funders that report grants to it. “On record” means captured in the filings we have parsed — a funder that does not e-file, or whose grant detail is not itemized, will not appear. Filings run roughly 12–24 months behind. Trends on this page end at FY2023, the last fiscal year that has finished arriving; later years are shown and marked, and move no figure. Data on this page was exported October 14, 2026. What this page cannot tell you · view filing