Company lists · Data refreshed September 2026

Top 25 Watershed protection organizations based in the United States

RevenueBase identified 395 watershed protection organizations headquartered in the United States as of September 2026 and tracks 3,412 professional contacts across them, including 1,431 with verified work emails. Portland is the largest hub.

This list covers watershed protection organizations headquartered in the United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 22, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 22, 2026 86% judged on-target in blind review
395Companies
3,412Contacts tracked
1,431Verified emails
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The 25 largest watershed protection organizations based in the United States

Ranked by team size
Top 25 of 395 watershed protection organizations based in the United States, ranked by team size, largest first. Data refreshed Sep 22, 2026. RevenueBase Smart Search rates how each company's information relates to watershed protection organizations: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Partial evidenceWashington, DC, United StatesHQ checked Sep 22, 202651-200366 contacts →

Partial evidence

“Since our founding during the campaign to pass the landmark Clean Water Act in 1972, Clean Water Action has worked to win strong health and environmental protections by bringing…”

Source: RevenueBase Database · checked Sep 22, 2026
2Indirect evidenceWashington, DC, United StatesHQ checked Sep 22, 202651-200147 contacts →

Indirect evidence

“American Rivers protects wild rivers, restores damaged rivers, and conserves clean water for people and nature.”

Source: RevenueBase Database · checked Sep 22, 2026
3Indirect evidenceChico, CA, United StatesHQ checked Sep 22, 202651-20081 contacts →

Indirect evidence

“River Partners brings life back to rivers.”

Source: RevenueBase Database · checked Sep 22, 2026
4Indirect evidencePortland, OR, United StatesHQ checked Sep 22, 202651-20058 contacts →

Indirect evidence

“The Freshwater Trust is focused on using insight to solve problems at the intersection of water and the economy.”

Source: RevenueBase Database · checked Sep 22, 2026
5Partial evidenceOssining, NY, United StatesHQ checked Sep 22, 202611-5054 contacts →

Partial evidence

“Riverkeeper is a member-supported watchdog organization dedicated to defending the Hudson River and its tributaries and protecting the drinking water supply of more than 9.5…”

Source: RevenueBase Database · checked Sep 22, 2026
6Indirect evidencePennington, NJ, United StatesHQ checked Sep 22, 202611-5051 contacts →

Indirect evidence

“Keeping water clean, safe and healthy is the heart of our mission.”

Source: RevenueBase Database · checked Sep 22, 2026
7Indirect evidenceNew York, NY, United StatesHQ checked Sep 22, 202611-5048 contacts →

Indirect evidence

“The Waterkeeper movement was started by a band of blue-collar fishermen on New York’s Hudson River in 1966.”

Source: RevenueBase Database · checked Sep 22, 2026
8Partial evidenceWalton, NY, United StatesHQ checked Sep 22, 202611-5042 contacts →

Partial evidence

“The Watershed Agricultural Council partners with hundreds of farm and forest landowners in the New York City Watershed region to ensure their lands stay within a working context.”

Source: RevenueBase Database · checked Sep 22, 2026
9Strong evidenceNaperville, IL, United StatesHQ checked Sep 22, 202611-5041 contacts →

Strong evidence

“We improve the health of our communities by preserving and restoring natural areas and open space, protecting rivers and watersheds, and promoting stewardship of our environment.”

Source: RevenueBase Database · checked Sep 22, 2026
10Indirect evidenceCoral Gables, FL, United StatesHQ checked Sep 22, 202611-5039 contacts →

Indirect evidence

“Protect the water you love.#MiamiWaterkeeper Miami Waterkeeper protects South Florida’s waters by advocating for resilient solutions grounded in science, rooted in nature, and…”

Source: RevenueBase Database · checked Sep 22, 2026
11Indirect evidenceSt Paul, MN, United StatesHQ checked Sep 22, 202611-5036 contacts →

Indirect evidence

“Great River Greening inspires, engages and leads local communities in conserving and caring for the land and water that enrich our lives.”

Source: RevenueBase Database · checked Sep 22, 2026
12Indirect evidenceEmmaus, PA, United StatesHQ checked Sep 22, 202611-5035 contacts →

Indirect evidence

“Our Mission: Protect and restore critical natural areas and waterways and educate the community to create a legacy of a healthy, sustainable environment for future generations.”

Source: RevenueBase Database · checked Sep 22, 2026
13Indirect evidenceBuffalo, NY, United StatesHQ checked Sep 22, 202611-5034 contacts →

Indirect evidence

“Buffalo Niagara WATERKEEPER’s mission is to protect and restore our water and surrounding ecosystems for the benefit of current and future generations.”

Source: RevenueBase Database · checked Sep 22, 2026
14Partial evidenceGreenfield, MA, United StatesHQ checked Sep 22, 2026n/a33 contacts →

Partial evidence

“Since 1952, CRC has been the voice for the Connecticut River watershed, from source to sea.”

Source: RevenueBase Database · checked Sep 22, 2026
15Partial evidenceBedminster, NJ, United StatesHQ checked Sep 22, 202611-5033 contacts →

Partial evidence

Protecting clean water in our rivers, our streams and our homes.”

Source: RevenueBase Database · checked Sep 22, 2026
16Strong evidenceFulton, MD, United StatesHQ checked Sep 22, 202611-5031 contacts →

Strong evidence

“The Center for Watershed Protection works to advance clean water resources and healthy ecosystems through responsible land and water management.”

Source: RevenueBase Database · checked Sep 22, 2026
17Indirect evidenceCosta Mesa, CA, United StatesHQ checked Sep 22, 202611-5030 contacts →

Indirect evidence

“Orange County Coastkeeper (Coastkeeper) is a nonprofit clean water organization that serves as a proactive steward of our fresh- and saltwater ecosystems.”

Source: RevenueBase Database · checked Sep 22, 2026
18Indirect evidenceWashington, United StatesHQ checked Sep 22, 202611-5028 contacts →

Indirect evidence

“Our mission is to protect the public’s right to clean water in the Potomac and Shenandoah Rivers and their tributaries.”

Source: RevenueBase Database · checked Sep 22, 2026
19Indirect evidenceBaltimore, MD, United StatesHQ checked Sep 22, 202611-5028 contacts →

Indirect evidence

“Blue Water Baltimore’s mission is to restore the quality of Baltimore’s rivers, streams and Harbor to foster a healthy environment, a strong economy and thriving communities.”

Source: RevenueBase Database · checked Sep 22, 2026
20Indirect evidenceEaston, MD, United StatesHQ checked Sep 22, 202611-5026 contacts →

Indirect evidence

“ShoreRivers is a nonprofit organization working to improve the health of Eastern Shore waterways through science-based advocacy, restoration, and education.”

Source: RevenueBase Database · checked Sep 22, 2026
21Indirect evidenceOakland, CA, United StatesHQ checked Sep 22, 202611-5026 contacts →

Indirect evidence

“International Rivers' mission is to protect rivers and defend the rights of communities that depend on them.”

Source: RevenueBase Database · checked Sep 22, 2026
22Indirect evidenceSacramento, CA, United StatesHQ checked Sep 22, 20261-1024 contacts →

Indirect evidence

“Friends of the River is California's only statewide river conservation organization.”

Source: RevenueBase Database · checked Sep 22, 2026
23Indirect evidencePortland, OR, United StatesHQ checked Sep 22, 202611-5024 contacts →

Indirect evidence

“SOMETIMES TO SAVE A RIVER, YOU HAVE TO BUY IT.”

Source: RevenueBase Database · checked Sep 22, 2026
24Indirect evidenceBristol, PA, United StatesHQ checked Sep 22, 202611-5024 contacts →

Indirect evidence

“The Delaware Riverkeeper Network has 21 staff members comprised of lawyers, advocates, scientists, technical experts, educators, and folks who care deeply about the River, so much…”

Source: RevenueBase Database · checked Sep 22, 2026
25Indirect evidenceSilver Spring, MD, United StatesHQ checked Sep 22, 202611-5024 contacts →

Indirect evidence

“Potomac Conservancy is a leading clean water advocate in the greater Washington, DC region.”

Source: RevenueBase Database · checked Sep 22, 2026

Showing 25 of 395 watershed protection organizations based in the United States

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Watershed protection organizations based in the United States at a glance

As of Sep 22, 2026
41.9%Verified-email coverage
8.6Average contacts per company
1-10Median size (employees)
2.3%Largest-city concentration · Portland
Sep 22, 2026Page data refreshed

Companies by employee count

1-10
306
11-50
74
51-200
9
201-500
1
501-1,000
1
10001+
1

Email recency for this list is measured worldwide rather than for United States, so it is reported there. Company counts and contact totals on this page are exact for United States, over 395 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among watershed protection organizations, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies
Companies headquartered in the United States whose own description of what they do matches “watershed protection organizations”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search
RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names watershed protection organizations), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude
Companies whose own description does not clearly place them among watershed protection organizations, and records with no verified work email. Companies headquartered outside United States are excluded even when they keep an office there.
Match quality
In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and its RevenueBase Smart Search rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking
Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification
Every listed company carries at least one verified work email, 1,431 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh
This page's figures were pulled from the company graph on September 22, 2026. Lists refresh periodically as the graph is re-checked.
Corrections
Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names watershed protection organizations, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many watershed protection organizations are there based in the United States?

RevenueBase identified 395 watershed protection organizations headquartered in the United States as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Clean Water Action, headquartered in Washington, tops this list with the largest team on record.

Which city has the most watershed protection organizations?

Portland leads with 9 headquartered companies, followed by Washington (6) and Seattle (5).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 1,431 verified decision-maker contacts tracked across these 395 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 22, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase Smart Search, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.