Elkhorn Slough Foundation
Public records show a registered, tax-exempt organization in good standing.
What it says it does
The Elkhorn Slough Foundation's mission is to conserve and restore Elkhorn Slough and its watershed, California's largest tidal salt marsh south of San Francisco Bay. Renowned for its extraordinary biodiversity, Elkhorn Slough features a dynamic working landscape intertwined with rich natural habitats. To achieve its mission, the Elkhorn Slough Foundation focuses on the direct acquisition and stewardship of key lands while collaborating with partnerorganizations and agencies. Together, they advance sound scientific research, deliver impactful education programs, and foster meaningful community engagement. As an accredited organization through the Land Trust Alliance Accreditation Commission, the Foundation upholds the highest standards in conservation and land stewardship.
- Income
- $8.5 million
- Spending
- $5.9 million
- Spent on programs
- 75%
- Reserves
- -2.1 months of spending
- Largest source of income
- donations and private grants, 48%
- Employees
- 45
- Volunteers
- 125
- Highest pay
- $198,680, executive director
Source: Form 990 for the year ending June 30, 2025, filed with the Internal Revenue Service. Rating method 2026.2. How we rate
Financial health
Fair: 55 out of 100. Higher than 14% of charities in its peer group (philanthropy, $1m to $10m).
Reserves
0 of 35Spendable reserves are negative: it owes or has committed more than it holds.
Debt
20 of 20It owes 2% of what it owns.
Living within its means
15 of 15Income exceeded spending by 32% of income.
Income trend
5 of 15Income fell 12% on the year before.
Spending floor
15 of 1575% of spending went to programs and raising each dollar of donations cost 6 cents.
Source: Form 990 for the year ending June 30, 2025, filed with the Internal Revenue Service. Rating method 2026.2. How we rate
Governance
Strong: 100 out of 100. Higher than 65% of charities in its peer group (philanthropy, $1m to $10m).
Independent board
25 of 2512 of 12 voting board members are independent.
Conflict of interest policy
15 of 15Has a written conflict of interest policy.
Whistleblower policy
8 of 8Has a written whistleblower policy.
Record keeping policy
7 of 7Has a written policy on keeping and destroying records.
Board minutes
5 of 5Keeps minutes of board meetings.
Board sees the tax return
10 of 10Gave the board a copy of this return before filing it.
Pay set independently
5 of 5Sets its chief executive's pay through independent review and comparison.
Independent check of accounts
15 of 15Its accounts were audited by an independent accountant.
No reported misuse
10 of 10Reports no diversion of assets, excess benefits or loans to insiders.
Source: Form 990 for the year ending June 30, 2025, filed with the Internal Revenue Service. Rating method 2026.2. How we rate
Impact evidence
Describes programs. Its tax return describes what it does but we have found no measurable results in it.
Programs described in its return (6)
- $970,779 spent. The Research and Monitoring (RAM) program on the Elkhorn Slough National Estuarine Research Reserve (ESNERR) is the primary vehicle for conducting water quality monitoring, habitat monitoring, and biological monitoring on the Reserve and throughout the Elkhorn Slough Watershed. The research and monitoring team has also been responsible for the publication of a series of peer-reviewed scientific publications, listed on the website: https://elkhornslough.org/reserve/research. This is an ongoing program funded by grants from NOAA and various state and federal agencies supporting restoration science. Elkhorn Slough Foundation administers these funds for the benefit of ESNERR and slough conservation in concert with the California Department of Fish and Wildlife. During the FY24-25 fiscal year, the Research team co-authored ten papers in scientific journals, studied metal contamination resulting from the Moss Landing Battery Fire, and continued to conduct marsh and oyster restoration in partnership with a local Tribe.
- $1.5 million spent. The Tidal Wetland Program (TWP) is a multi-agency effort addressing one of the most critical ecological challenges in the tidal portions of Elkhorn Slough: the dramatic loss of vegetated marshland caused by historic modifications to the slough's hydrology. Collaborating with over 100 scientists, resource managers, local residents, and other stakeholders, TWP has employed an ecosystem-based management approach to halt habitat loss and restore natural functions to the slough system. This effort has resulted in the implementation of more natural tidal flow to the Parson's Slough complex and Whistlestop within the Elkhorn Slough National Estuarine Research Reserve, protecting over 450 acres of tidal wetlands and keeping public access to the main channel of the slough open.Ongoing work focuses on restoring wetlands through the beneficial reuse of clean sediments to rebuild subsided marshes, while also exploring the potential for carbon sequestration in these restored habitats. One key initiative, the Hester Marsh restoration, is revitalizing 150 acres of formerly diked and degraded marsh. This project involves elevating the subsided marsh plain by adding soil and bringing it to the upper end of the tidal frame to support marsh vegetation. The elevation is designed to accommodate projected sea-level rise well into the next century. Looking ahead, the Tidal Wetland Program plans to integrate infrastructure resilience into its broader ecosystem resilience efforts.
- $1.1 million spent. The Land Stewardship Program oversees the restoration, maintenance, and management of more than 5,900 acres within the Elkhorn Slough watershed. Over the past year, the Stewardship team collaborated with dozens of community volunteers and the California Conservation Corps to carry out a diverse range of conservation efforts. These activities included removing tons of trash and debris, controlling invasive weed species, monitoring key lands and wildlife, mapping natural resources, and propagating native plants. Through this work, the program has successfully transformed hundreds of acres of degraded landscapes, such as eroded sandhills, former eucalyptus groves, and abandoned farmland, into thriving, healthy habitats. Simultaneously, the program preserves the intact natural areas of the slough, ensuring their ecological vitality for the future. In the last fiscal year, the team achieved major milestones, including producing and out-planting millions of native seeds, highlighted by an 8-acre seeding project in the Hester grassland, and removing over 30 acres of fire-prone, invasive eucalyptus trees to reduce catastrophic wildfire risk and protect native plants and animals.
- $153,358 spent. Since 1982, the Elkhorn Slough Foundation (ESF) has led efforts to conserve and restore Elkhorn Slough and its watershed. Through the Land Acquisition program, ESF has protected over four thousand acres of key lands through an active program of acquiring fee and easement interests in properties in the watershed. Public interest conservation values secured by these acquisitions include open space, wildlife and rare species habitat, viewshed protection, groundwater recharge, and water quality improvement. By working in close collaboration with other agencies and organizations, ESF has been able to expand funding and support for Elkhorn Slough protection and conservation management. In the 2024-'25 fiscal year our accomplishments include: 1) renewed our accreditation with the Land Trust Accreditation Commission, 2) added a new strategic objective to protect wildlife connectivity to the upper watershed, 3) mapped and analyzed five properties totaling about 900 acres in the new connectivity area for potential acquisition, and 4) made steady progress on several transactions in the watershed totaling about 1,500 acres to protect wetlands, grasslands, oak woodland and sustainable farmland.
- $535,723 spent. ESF's Education and Public Relations Program (EPR) includes a vibrant social media presence and various public talks, walks, and programs designed for school and community groups. Each year, we support more than 20 outside organizations by providing volunteer opportunities for groups such as Scouting America, church groups, school groups, corporate volunteer programs, and more. Our outdoor education program engages over 150 local students by helping them build meaningful relationships with their peers and the natural environment. For example, students from Hall Elementary School have the opportunity to regularly experience open spaces through ~15 half-day visits per school year. In 2025, we doubled the number of local university students involved in our community programs from 23 to 46. These students, from California State University Monterey Bay, are completing Community Engagement Capstone Projects by helping us deliver programming to elementary school students and families in the community. Among other things, these students are learning how to develop culturally relevant programs that are consciously co-designed with participants, connecting families to the land and water in their communities through projects that remove barriers to access.We also continue to strengthen partnerships with like-minded organizations to conserve and restore Elkhorn Slough and educate the community about its ecological significance. This includes active participation in Juntxs En La Naturaleza, a collaborative group that includes the Monterey Bay Aquarium, Bird School Project, Latino Outdoors, Puentes Nature, Milpa, Regeneracion, and others. Together, we provide access to nature for 300+ historically underserved families in our community. Additionally, we support education and volunteer programs at the Elkhorn Slough Reserve, which served 2,750 students and 21,000 visitors in 2025.
- $193,762 spent. The Training and Engagement Program (TE) is an ongoing ESNERR program, funded primarily by NOAA, that partners with other organizations to bring together diverse participants, including farmers, ranchers, private and public land managers, conservationists, regulatory and agency personnel, and scientists, to discuss and explore solutions to key natural resource management issues within the Central Coast region. TE also offers a suite of highly sought-after trainings on the biology and management of threatened and endangered wildlife species, such as California tiger salamanders, foothill yellow-legged frog, and western burrowing owls. In FY2024-2025, TE hosted or co-hosted seven training workshops that brought together approximately 380 environmental professionals and community members. TE builds collaborative networks that develop expertise and leadership to better conserve natural and working lands throughout the Elkhorn Slough watershed, the Central Coast region, and statewide.
Source: Form 990 for the year ending June 30, 2025, filed with the Internal Revenue Service. Rating method 2026.2. How we rate
Legitimacy checks
Is it registered with the IRS? Passed.
Listed in the IRS master file of tax-exempt organizations as a 501(c)(3) charitable organization.
Source: Exempt Organizations Business Master File, Internal Revenue Service, file dated October 13, 2026.
Has the IRS revoked its tax-exempt status? Passed.
Not on the IRS automatic revocation list.
Source: Automatic revocation of exemption list, Internal Revenue Service, file dated October 13, 2026.
Are donations tax-deductible? Passed.
On the IRS list of organizations eligible to receive tax-deductible contributions.
Source: Publication 78 data: organizations eligible for tax-deductible contributions, Internal Revenue Service, file dated October 13, 2026.
Is it keeping up with its IRS filings? Passed.
Most recent return on file covers the year ending June 2025.
Source: Exempt Organizations Business Master File, Internal Revenue Service, file dated October 13, 2026.
How long has it been tax-exempt? Passed.
Recognized by the IRS since December 1994.
Source: Exempt Organizations Business Master File, Internal Revenue Service, file dated October 13, 2026.
Is it in good standing with state regulators? Passed.
Not on California's list of charities barred from soliciting. Other states are not yet checked.
Source: May Not Operate or Solicit for Charitable Purposes list, California Attorney General, Registry of Charities and Fundraisers, file dated October 21, 2026.
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