Company lists · Data refreshed September 2026

Top 25 Environmental nonprofits based in Seattle, United States

Name: Environmental nonprofits based in Seattle, United States
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 19, 2026 88 companies tracked

RevenueBase identified 88 environmental nonprofits headquartered in Seattle, United States as of September 2026 and tracks 1,157 professional contacts across them, including 568 with verified work emails. Washington is the largest hub.

This list covers environmental nonprofits headquartered in Seattle, 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 19, 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 19, 2026 86% judged on-target in blind review

88Companies

1,157Contacts tracked

568Verified emails

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The 25 largest environmental nonprofits based in Seattle, United States

Ranked by team size

Top 25 of 88 environmental nonprofits based in Seattle, United States, ranked by team size, largest first. Data refreshed Sep 19, 2026. RevenueBase Smart Search rates how each company's information relates to environmental nonprofits: 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.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	Cascadia Consulting Group	Partial evidence	Seattle, WA, United StatesHQ checked Sep 19, 2026	51-200	110 contacts →
	Partial evidence “Cascadia Consulting Group is a majority women-owned consulting firm specializing in environmental and sustainability solutions.” Source: RevenueBase Database · checked Sep 19, 2026
2	Greater Good Charities	Indirect evidence	Seattle, WA, United StatesHQ checked Sep 19, 2026	51-200	94 contacts →
	Indirect evidence “Greater Good Charities is an independent 501(c)(3) charitable organization devoted to improving the health and well-being of people, pets, and the planet.” Source: RevenueBase Database · checked Sep 19, 2026
3	Earthcorps	Partial evidence	Seattle, WA, United StatesHQ checked Sep 19, 2026	11-50	83 contacts →
	Partial evidence “EarthCorps cultivates leaders and community partnerships to advance environmental justice.” Source: RevenueBase Database · checked Sep 19, 2026
4	GRIST	Partial evidence	Seattle, WA, United StatesHQ checked Sep 19, 2026	51-200	69 contacts →
	Partial evidence “Grist is a nonprofit, independent media organization dedicated to reporting on climate change.” Source: RevenueBase Database · checked Sep 19, 2026
5	Forterra NW	Indirect evidence	Seattle, WA, United StatesHQ checked Sep 19, 2026	11-50	68 contacts →
	Indirect evidence “OUR MISSION Forterra innovates and scales land-based solutions to address the climate crisis and support equitable, green, and prosperous communities.” Source: RevenueBase Database · checked Sep 19, 2026
6	NIA Tero	Indirect evidence	Seattle, WA, United StatesHQ checked Sep 19, 2026	11-50	54 contacts →
	Indirect evidence “The governance systems and cultural wisdom sustained by Indigenous Peoples have significant impact on the health of the ecosystems where they live.” Source: RevenueBase Database · checked Sep 19, 2026
7	Washington Conservation Action	Partial evidence	Seattle, WA, United StatesHQ checked Sep 19, 2026	11-50	51 contacts →
	Partial evidence “Washington Conservation Action’s mission is to advocate for environmental progress and justice through actions that mobilize the public, elect champions for the environment, and…” Source: RevenueBase Database · checked Sep 19, 2026
8	Mast Reforestation	Indirect evidence	Seattle, WA, United StatesHQ checked Sep 19, 2026	11-50	47 contacts →
	Indirect evidence “As wildfires destroy more forestland every year, Mast is scaling post-wildfire reforestation in Western North America.” Source: RevenueBase Database · checked Sep 19, 2026
9	Give Volunteers	Indirect evidence	Seattle, WA, United StatesHQ checked Sep 19, 2026	11-50	44 contacts →
	Indirect evidence “Our meaningful travel combines sustainable volunteer projects, cultural immersion, and epic adventure so you can discover the world and your purpose in it.” Source: RevenueBase Database · checked Sep 19, 2026
10	Conservation Northwest	Indirect evidence	Seattle, WA, United StatesHQ checked Sep 19, 2026	11-50	33 contacts →
	Indirect evidence “Our mission is simple: connect the big landscapes, restore iconic wildlife and protect our natural heritage for future generations.” Source: RevenueBase Database · checked Sep 19, 2026
11	ECOSS	Partial evidence	Seattle, WA, United StatesHQ checked Sep 19, 2026	11-50	25 contacts →
	Partial evidence “Mission: ECOSS is devoted to promoting environmental justice and sustainability in an effort to build immigrant and refugee communities that can shape their environmental futures.” Source: RevenueBase Database · checked Sep 19, 2026
12	Front And Centered	Partial evidence	Seattle, WA, United StatesHQ checked Sep 19, 2026	11-50	23 contacts →
	Partial evidence “Communities of color, people with lower incomes, and indigenous people are on the frontlines of climate and environmental change.” Source: RevenueBase Database · checked Sep 19, 2026
13	Seattle Parks Foundation	Indirect evidence	Seattle, WA, United StatesHQ checked Sep 19, 2026	11-50	22 contacts →
	Indirect evidence “Seattle Parks Foundation partners with community to champion thriving and equitable parks and public spaces.” Source: RevenueBase Database · checked Sep 19, 2026
14	Birds Connect Seattle	Indirect evidence	Seattle, WA, United StatesHQ checked Sep 19, 2026	11-50	22 contacts →
	Indirect evidence “Birds Connect Seattle advocates and organizes for cities where people and birds thrive.” Source: RevenueBase Database · checked Sep 19, 2026
15	Toxic-Free Future	Partial evidence	Seattle, WA, United StatesHQ checked Sep 19, 2026	11-50	21 contacts →
	Partial evidence “Toxic-Free Future is a national leader in environmental health research and advocacy.” Source: RevenueBase Database · checked Sep 19, 2026
16	Washington Journal Of Social & Environmental Justice	Partial evidence	Seattle, WA, United StatesHQ checked Sep 19, 2026	11-50	21 contacts →
	Partial evidence “The Washington Journal of Social & Environmental Justice publishes legal scholarship examining how communities interact with each other and the environment with the goal of…” Source: RevenueBase Database · checked Sep 19, 2026
17	Washington's National Park Fund	Indirect evidence	Seattle, WA, United StatesHQ checked Sep 19, 2026	1-10	16 contacts →
	Indirect evidence “Washington's National Park Fund's mission is to raise funds to preserve and enhance the natural beauty, cultural heritage, and recreational opportunities of Mount Rainier, North…” Source: RevenueBase Database · checked Sep 19, 2026
18	Pollution Prevention Resource Center	Partial evidence	Seattle, WA, United StatesHQ checked Sep 19, 2026	11-50	14 contacts →
	Partial evidence “The Pollution Prevention Resource Center (PPRC), a 501(c)(3) nonprofit organization, is a leading source of high-quality, unbiased pollution prevention information.” Source: RevenueBase Database · checked Sep 19, 2026
19	Spark Northwest	Indirect evidence	Seattle, WA, United StatesHQ checked Sep 19, 2026	1-10	13 contacts →
	Indirect evidence “Spark Northwest accelerates the shift to clean energy one community at a time.” Source: RevenueBase Database · checked Sep 19, 2026
20	Duwamish River Community Coalition	Partial evidence	Seattle, WA, United StatesHQ checked Sep 19, 2026	1-10	13 contacts →
	Partial evidence “DRCC has never delved into the delineation between Superfund site and affected community-in our view, environmental justice concerns inextricably link harmful pollutant practices…” Source: RevenueBase Database · checked Sep 19, 2026
21	Seattle Reconomy	Partial evidence	Seattle, WA, United StatesHQ checked Sep 19, 2026	1-10	13 contacts →
	Partial evidence “Seattle REconomy is a nonprofit promoting sustainability and community through access to tools, ranging from saws and drills to mowers and pressure washers, as well as classes…” Source: RevenueBase Database · checked Sep 19, 2026
22	Wilburforce Foundation	Partial evidence	Seattle, WA, United StatesHQ checked Sep 19, 2026	11-50	12 contacts →
	Partial evidence “WILBURFORCE FOUNDATION is an environmental services company based out of 2034 Nw 56Th St,# 300, Seattle, Washington, United States.” Source: RevenueBase Database · checked Sep 19, 2026
23	Washington Wild	Indirect evidence	Seattle, WA, United StatesHQ checked Sep 19, 2026	1-10	12 contacts →
	Indirect evidence “Washington Wild protects and restores wild lands and waters in Washington State through advocacy, education, and civic engagement.” Source: RevenueBase Database · checked Sep 19, 2026
24	Sustainable Seattle S2	Indirect evidence	Seattle, WA, United StatesHQ checked Sep 19, 2026	1-10	12 contacts →
	Indirect evidence “Read our December 2023 welcome to new Board Members: https://conta.cc/3t6WFGX Learn about our 2023 accomplishments and how you can support our work: https://conta.cc/4asyyDB…” Source: RevenueBase Database · checked Sep 19, 2026
25	Basilica BIO	Partial evidence	Seattle, WA, United StatesHQ checked Sep 19, 2026	1-10	11 contacts →
	Partial evidence “How do we build resilience in frontline communities most affected by the environmental crisis?” Source: RevenueBase Database · checked Sep 19, 2026

RevenueBase Smart Search

RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: environmental nonprofits. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.

Strong evidence: The company's own public description of its business names environmental nonprofits.
Partial evidence: Its own public description names part of environmental nonprofits, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name environmental nonprofits. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.

RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.

Showing 25 of 88 environmental nonprofits based in Seattle, United States

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Environmental nonprofits based in Seattle, United States at a glance

As of Sep 19, 2026

49.1%Verified-email coverage

13.1Average contacts per company

1-10Median size (employees)

221.6%Largest-city concentration · Washington

Sep 19, 2026Page data refreshed

Companies by employee count

1-10

11-50

51-200

Email recency for this list is measured across the whole United States list rather than for Seattle, so it is reported there. Company counts and contact totals on this page are exact for Seattle, over 88 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 environmental nonprofits, 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 Seattle, United States whose own description of what they do matches “environmental nonprofits”. 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 environmental nonprofits), 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 environmental nonprofits, and records with no verified work email. Companies headquartered outside Seattle 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, 568 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 19, 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.

Environmental nonprofits by metro in the United States

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 environmental nonprofits, 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 environmental nonprofits are there based in Seattle, United States?

RevenueBase identified 88 environmental nonprofits headquartered in Seattle, 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?

Cascadia Consulting Group, headquartered in Seattle, tops this list with the largest team on record.

Which city has the most environmental nonprofits?

Washington leads with 195 headquartered companies, followed by New York (194) and San Francisco (126).

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 568 verified decision-maker contacts tracked across these 88 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 19, 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.