TOWNSHIP 37, Maine — In the forests of Down East Maine there are areas so remote that the locations have no names and the roads are merely numbers.

In Township 37, on Road 52-00-0 — roughly halfway between Route 9 and Grand Lake Stream — a group of researchers, high school and college interns, landowners and construction companies are working to restore the upstream habitat of sea-run fish in the Machias River watershed.

On Road 52-00-0, locally called “The 52,” a dusty, gravel road used primarily by loggers, a researcher climbs down an embankment to a pure, cold salmon stream. A massive culvert cuts under the road but it is bottomless, allowing the stream bed to flow naturally and the sea-run fish — salmon, shad, striped bass, alewives, eels and seven other species — to migrate upstream to spawn.

“This is success. This is critical habitat,” Katrina Mueller, outreach coordinator of Project SHARE, said Thursday.

Beyond that, she said, the restoration effort is using $1.7 million in federal stimulus funds to pump dollars and jobs into the Washington County economy.

The culvert carries Honeymoon Brook and was replaced last year as part of a multiyear restoration project spearheaded by Project SHARE, which is a joint effort of the National Oceanic and Atmospheric Administration’s National Marine Fisheries Service, the National Resources and Conservation Service and the Maine Department of Marine Resources.

Those agencies are working collaboratively with the U.S. Fish and Wildlife Service on the project.

Mueller said up to 50 culverts would be replaced this year; 38 were done last year. Hundreds of native trees will be planted, and a precise and comprehensive map and inventory of the watershed is under way.

In addition, six road crossings will be decommissioned and one Machias River side channel will be reconnected to the mainstream river.

Stopping along The 52, Mueller pointed to a wide swath of dead trees alongside the road. She explained that when a culvert was placed too high under the road — perched, she calls it — the natural flow of the stream was altered. Water backed up and killed the trees. More importantly, the culvert prevented fish migration by “pinching the stream,” Mueller said.

“That connectivity, from the sea to the spawning grounds, is vital for juvenile sea-run fish,” she explained. Twelve fish varieties use the Machias River watershed, including salmon, striped bass, alewives and eels.

The watershed’s West Branch Machias River is listed as the 2010 National Fish Habitat Action Plan’s 10 “Waters to Watch.” The list identifies bodies of water that are improving through the conservation efforts of regional partnerships of community groups, nonprofit organizations, local watershed groups, Native American tribes, and state and federal agencies.

Working with landowners, USFW and Project SHARE are replacing the mispositioned culverts in the Machias River watershed with arched domes with open bottoms, structures designed to restore natural stream function. A bonus is that because the bottom of each new culvert is open, it will not rust out and is expected to last 75 years.

“This will open up over 70 stream miles of critical headwater habitats that influence the downstream watercourse and provide food and shelter for juvenile salmon and also native Eastern brook trout and other species,” Mueller said.

Although the projects are geared toward the recovery of salmon and to enhance brook trout habitats, Mueller said they also would restore ecological stream processes that ultimately will benefit nearly all animals — turtles, fur bearers, reptiles — that use the streams as migratory corridors.

The project’s interns already have seen bear, moose, deer and bobcats in the areas they are mapping.

Once a culvert has been replaced, Mueller said, the water begins to flow freely and the natural habitat is quickly restored. She said that within a matter of weeks positive effects can be seen.

“These, for the most part, return to very healthy streams,” Project SHARE fisheries’ biologist Ben Naumann said. “And because of the great cooperation between all the agencies, we are able to accomplish so much work.”

Most of the projects are centered on Stud Mill Road and The 52. All of the sites are north of Route 9.

Mueller said five high school students from Eastport, one from Hampden and two college students from the University of Maine are living in a tent city about 15 miles into the woods as they participate on the project.

Local contractors are doing the excavation work and Mueller said about 40 people are employed, some full time and others part time, on the project.

A second phase of the project, Mueller said, involves identifying log dams put in the tributaries decades ago when logs were floated down the rivers for processing.

“We are finding lots of remnants of these dams,” she said. “They are made of wood and boulders and they were used to hold up the water to round up the logs and then opened to flush the logs downstream,” she said. Each of these log dams must be removed by hand.

Mueller said that when the logs were allowed down the streams and rivers, the habitat became homogenized. Dead water was created behind the dams, which caused sediment to settle.

“This is not conducive to sea-run fish. They prefer a cool, flowing stream,” Mueller said.

Steve Koenig of Eastport, executive director of Project SHARE, said that replacing the culverts is meaningless unless the log dams above and below them are removed.

“It would be useless to fix the road crossings and not fix the dams,” he said.

The projects are being watched by landowners across the state as potential models of fish habitat restoration, Mueller said. “We are getting calls every day by property owners asking how the project can expand into their counties.”