A pair of ducks took off in the bright spring morning sunlight, flew a little ways, then splashed down again at Wimisink Preserve.

There was a red-winged blackbird calling over a full chorus of peepers. There were wood chips left where the wetland's resident beavers had been feeding.

People just driving by the preserve along Route 39 in Sherman would catch almost none of this. After Earth Day on April 22, they'll have a nice reason to stop.

The Naromi Land Trust, which owns the preserve, is building a 300-foot-long boardwalk into the Wimisink wetland, thanks to a $125,000 grant from the Housatonic River Basin Natural Resources Restoration project.

The land trust will dedicate it on Earth Day.

The boardwalk is shaped like a big U. It starts at a new parking lot that's been built adjacent to Route 39 and ends in a viewing platform in the wetland.

It will be wheelchair-accessible -- one of the few trails in the area designed for that use.

"But it's also for mothers with strollers," said Marge Josephson, president of the Naromi Land Trust. "It's for anyone who doesn't feel safe walking on uneven ground."

And for anyone who likes a pretty wetland.

Hunter Brawley, the land manager of the Naromi Land Trust, said the 55-acre preserve is part of the Marble Valley geological formation that runs along the New York-Connecticut border from northern Ridgefield to Stockbridge, Mass.

Because the limestone/marble formations in the valley create a far less acidic soil and water than in the rest of Connecticut, unusual wildflowers and plants grow in parts of the valley. The formation can also harbor different fauna to go with its flora.

And it's a wetland. In spring, it get warblers and duck migrating north. Both American bitterns and Virginia rails -- shy marsh birds -- have been seen at the preserve in past years.

"It should be good habitat for bog turtles, although we've never seen one there," Brawley said. "We're looking for leopard frogs there now."

The money paying for the boardwalk is part of the $7.5 million that the General Electric Co. gave the state in restoration grants in 2000 as part of its settlement for its pollution of the Housatonic River with polychlorinated biphenyls, or PCBs.

Because Wimisink Brook feeds into the Housatonic in the Gaylordsville section in New Milford, the boardwalk project was eligible for funding.

Peter Jensen, a professional trail-builder who has made several boardwalks, is creating this one of black locust wood -- harder to deal with, but very durable.

"It'll last one day less than eternity," Jensen said.

Because the boardwalk is to be wheelchair accessible, Jensen said, he designed it with very gentle slopes broken up by flat areas. The observation deck at the end will be big enough so that a wheelchair can turn around there.

Jensen has been building trails since the 1970s, forming his own company in 1988. In recent years, he said, he's been building more boardwalks.

"When you think about it, what are the areas left for trails now?" Jensen said. "We do more work now in sensitive areas -- ridge lines, stream crossings, floodplains."

Workers are outside in beautiful settings. But one of Jensen's crew, Erin Amadon, said sometimes ear plugs are required.

"The peepers are so loud," she said.

bmiller@newstimes.com; 203-731-3345