Penobscot River Restoration (Maine)
After two dams came out of Maine's Penobscot River, nearly 5.93 million river herring climbed the Milford fish lift in 2025, up from about 590,000 in 2015 (Maine DMR).
Image: NASA (iss072e394484, Dec. 18, 2024).
Last reviewed: 3 sources cited
Explain Like I'm 10
- Dams on the Penobscot River blocked fish from swimming up to lay their eggs.
- People took out two dams and built new ways for fish to get past others.
- Now millions of fish swim up the river again each year.
The Five W's of the Penobscot River Restoration
Who
The Penobscot River Restoration Trust, a nonprofit, with the Penobscot Indian Nation, the State of Maine, federal agencies, conservation groups and a hydropower company.
What
Removing the Great Works and Veazie dams, adding a fish lift at Milford Dam and a fish bypass around Howland Dam, while keeping hydropower.
Source: Marine and Coastal Fisheries, Fish assemblages in the Penobscot River a decade after dam removal
When
Great Works Dam came out in 2012, Veazie Dam in 2013, and the Howland bypass was built in 2016.
Source: Marine and Coastal Fisheries, Fish assemblages in the Penobscot River a decade after dam removal
Where
The Penobscot River, Maine's largest river, which drains about a quarter of the state into Penobscot Bay.
Why
For centuries, dams blocked sea-run fish from their spawning grounds. The project improves access to nearly 1,000 miles of habitat for 11 native sea-run fish species.
Impact Statement
Nonprofit solution · active
River herring counted at the Milford fish lift rose from 589,645 in 2015 to 5,927,002 in 2025 (Maine Department of Marine Resources).
Source: Maine Department of Marine Resources, trap counts 2015-2025
For Further Information: Maine Department of Marine Resources, trap counts 2015-2025
Before restoration, an average of just 556 river herring returned each year (1978-2012). By 2018 the count passed 2.3 million.
How This Saves People & the Planet
For People
Reconnecting the river rejoins the Penobscot Indian Nation's homeland with the Atlantic Ocean and revives fishing and paddling traditions (Penobscot River Restoration Trust).
Source: Penobscot River Restoration Trust
For Nature
Eight of the 12 sea-run fish species native to the Penobscot have used the new Milford fish lift to swim upriver (Marine and Coastal Fisheries).
Source: Marine and Coastal Fisheries, Fish assemblages in the Penobscot River a decade after dam removal
Learn More About the Penobscot River
Want to go deeper? The Penobscot River Restoration Trust has the full story.
For Further InformationRelated Solutions
More solutions like this one, matched by meaning.
Help This Work
Links go straight to the organization. Saving Planets doesn't receive any of the money.