Company lists · Data refreshed September 2026

Top 25 Environmental law organizations based in the United States

RevenueBase identified 915 environmental law organizations headquartered in the United States as of September 2026 and tracks 17,457 professional contacts across them, including 8,914 with verified work emails. Washington is the largest hub.

This list covers environmental law 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 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
915Companies
17,457Contacts tracked
8,914Verified emails
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The 25 largest environmental law organizations based in the United States

Ranked by team size
Top 25 of 915 environmental law organizations based in the 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 law 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 evidencePhiladelphia, PA, United StatesHQ checked Sep 19, 20261,001-5,0001,682 contacts →

Partial evidence

“Ballard Spahr LLP, an Am Law 100 law firm with more than 750 lawyers in 19 U.S.”

Source: RevenueBase Database · checked Sep 19, 2026
2Partial evidenceNew York, NY, United StatesHQ checked Sep 19, 2026501-1,000942 contacts →

Partial evidence

“NRDC is the nation's most effective environmental action organization.”

Source: RevenueBase Database · checked Sep 19, 2026
3Partial evidenceSan Francisco, United StatesHQ checked Sep 19, 2026501-1,000672 contacts →

Partial evidence

“Earthjustice is a non-profit public interest law organization dedicated to protecting the magnificent places, natural resources, and wildlife of this earth, and to defending the…”

Source: RevenueBase Database · checked Sep 19, 2026
4Strong evidenceCharleston, WV, United StatesHQ checked Sep 19, 2026201-500330 contacts →

Strong evidence

“Jackson Kelly PLLC is a national law firm representing leading global corporations, national companies, entrepreneurs and individuals in areas of law such as environmental…”

Source: RevenueBase Database · checked Sep 19, 2026
5Indirect evidenceWashington, DC, United StatesHQ checked Sep 19, 2026201-500328 contacts →

Indirect evidence

“Beveridge & Diamond’s 170+ lawyers in 7 U.S.”

Source: RevenueBase Database · checked Sep 19, 2026
6Partial evidenceClovis, CA, United StatesHQ checked Sep 19, 2026n/a233 contacts →

Partial evidence

“Appl Inc is an environmental services company based out of 908 N Temperance Ave, Clovis, CA, United States.”

Source: RevenueBase Database · checked Sep 19, 2026
7Partial evidenceWashington, DC, United StatesHQ checked Sep 19, 202651-200230 contacts →

Partial evidence

“Keller and Heckman, founded in 1962, has a broad practice in the areas of regulatory law, public policy, and litigation, serving both domestic and international clients.”

Source: RevenueBase Database · checked Sep 19, 2026
8Indirect evidenceWashington, DC, United StatesHQ checked Sep 19, 202651-200218 contacts →

Indirect evidence

“LCV believes our earth is worth fighting for because everyone has a right to clean air, water, and a safe, healthy community.”

Source: RevenueBase Database · checked Sep 19, 2026
9Partial evidenceLos Angeles, CA, United StatesHQ checked Sep 19, 2026201-500204 contacts →

Partial evidence

“Musick Peeler, a premier law firm with over 80 attorneys across five offices in major commercial centers of California, exemplifies excellence in legal service.”

Source: RevenueBase Database · checked Sep 19, 2026
10Indirect evidenceWashington, DC, United StatesHQ checked Sep 19, 202651-200199 contacts →

Indirect evidence

“The Wilderness Society (TWS) is the leading conservation organization working to protect America’s wild places and public lands for the health of local communities, wildlife, and…”

Source: RevenueBase Database · checked Sep 19, 2026
11Indirect evidenceBoston, MA, United StatesHQ checked Sep 19, 202651-200174 contacts →

Indirect evidence

“Since 1966, CLF has taken on powerful opponents who would pollute our air and water and squander our resources.”

Source: RevenueBase Database · checked Sep 19, 2026
12Strong evidenceWashington, DC, United StatesHQ checked Sep 19, 202651-200174 contacts →

Strong evidence

“Van Ness Feldman is a nationally recognized mid-sized law firm specializing in the areas of energy, environment, and natural resources law and policy, with offices in Washington…”

Source: RevenueBase Database · checked Sep 19, 2026
13Indirect evidenceRocklin, CA, United StatesHQ checked Sep 19, 202651-200166 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 19, 2026
14Indirect evidenceLos Angeles, CA, United StatesHQ checked Sep 19, 202651-200157 contacts →

Indirect evidence

“From civil litigation to business transactions, Haight Brown & Bonesteel LLP provides practical and effective resolution advice to the most perplexing disputes, ranging from early…”

Source: RevenueBase Database · checked Sep 19, 2026
15Partial evidenceWashington, DC, United StatesHQ checked Sep 19, 202611-50144 contacts →

Partial evidence

“EARTHDAY.ORG’s mission is to diversify, educate and activate the environmental movement worldwide.”

Source: RevenueBase Database · checked Sep 19, 2026
16Partial evidenceElmhurst, IL, United StatesHQ checked Sep 19, 202651-200140 contacts →

Partial evidence

“Since the passage of original environmental legislation nearly four decades ago, both private and public industry have turned to Mostardi Platt for guidance in complying with air…”

Source: RevenueBase Database · checked Sep 19, 2026
17Partial evidenceHonolulu, HI, United StatesHQ checked Sep 19, 202651-200138 contacts →

Partial evidence

“Cades Schutte is a full-service law firm in Hawai‘i with around 80 attorneys.”

Source: RevenueBase Database · checked Sep 19, 2026
18Indirect evidenceNewark, NJ, United StatesHQ checked Sep 19, 202651-200126 contacts →

Indirect evidence

“With attorneys admitted to the bar in New York, New Jersey, Pennsylvania, and the District of Columbia, and with offices across the region, Genova Burns LLC provides special…”

Source: RevenueBase Database · checked Sep 19, 2026
19Partial evidenceChicago, IL, United StatesHQ checked Sep 19, 202651-200125 contacts →

Partial evidence

“EDELSON PC is a law firm concentrating on high-stake’s plaintiff’s work ranging from class and mass actions to public client investigations and prosecutions.”

Source: RevenueBase Database · checked Sep 19, 2026
20Partial evidenceWashington, DC, United StatesHQ checked Sep 19, 202651-200120 contacts →

Partial evidence

“The Environmental Working Group is a non-profit, non-partisan organization dedicated to protecting human health and the environment.”

Source: RevenueBase Database · checked Sep 19, 2026
21Partial evidenceSeattle, WA, United StatesHQ checked Sep 19, 202651-200110 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
22Partial evidenceChantilly, VA, United StatesHQ checked Sep 19, 2026201-500104 contacts →

Partial evidence

“Established in 1983, TechLaw provides environmental and management consulting services to the public sector nationwide.”

Source: RevenueBase Database · checked Sep 19, 2026
23Partial evidenceCharlotte, NC, United StatesHQ checked Sep 19, 202651-200103 contacts →

Partial evidence

“Hart & Hickman PC provides environmental consulting services to commercial, industrial, and governmental clients throughout the Southeast US.”

Source: RevenueBase Database · checked Sep 19, 2026
24Strong evidenceWashington, DC, United StatesHQ checked Sep 19, 202611-50102 contacts →

Strong evidence

“The Environmental Law Institute (ELI) makes law work for people, places, and the planet.”

Source: RevenueBase Database · checked Sep 19, 2026
25Strong evidenceCosta Mesa, CA, United StatesHQ checked Sep 19, 202651-20098 contacts →

Strong evidence

“Public agencies and businesses have been relying on Chambers Group to keep them in compliance with applicable federal, state, and/or local environmental laws, regulations, and…”

Source: RevenueBase Database · checked Sep 19, 2026

Showing 25 of 915 environmental law organizations based in the United States

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Environmental law organizations based in the United States at a glance

As of Sep 19, 2026
51.1%Verified-email coverage
19.1Average contacts per company
1-10Median size (employees)
6.2%Largest-city concentration · Washington
Sep 19, 2026Page data refreshed

Companies by employee count

1-10
564
11-50
266
51-200
67
201-500
10
501-1,000
5
1,001-5,000
3

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 915 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 law 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 “environmental law 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 environmental law 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 environmental law 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, 8,914 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 law organizations by metro

  • Environmental law organizations in Washington57

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 law 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 environmental law organizations are there based in the United States?

RevenueBase identified 915 environmental law 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?

Ballard Spahr LLP, headquartered in Philadelphia, tops this list with the largest team on record.

Which city has the most environmental law organizations?

Washington leads with 57 headquartered companies, followed by Austin (24) and New York (24).

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 8,914 verified decision-maker contacts tracked across these 915 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.