"Tension!"

The barked order echoed last Saturday in a heavily wooded valley in North Stonington, where a crew of volunteers armed with assorted tools and pulling devices gathered at a fast-flowing stream.

In response, Ralph Davidson, one of the workers, began cranking the bar of a grip hoist back and forth, tightening a half-inch-thick steel cable connected to a chain wrapped around an enormous boulder.

The granite chunk, about the size of a kitchen table, inched forward, partially suspended by a separate line stretched between two trees.

"Slack!" cried Wayne Fogg, head of the crew, and Davidson repositioned the grip hoist lever. The cable began to loosen so that Fog and the others could maneuver the boulder with pry bars.

The giant rock was one of four stepping stones we volunteers placed across Yawbucs Brook as part of a project organized by the Connecticut Forest & Park Association (CFPA), a private, nonprofit conservation organization that helps secure rights of way for and maintains all 825 miles blue-blazed hiking trails throughout the state.

Bob Andrews of Preston, a CFPA volunteer who with his daughter Crystal is responsible for maintaining trails in eastern Connecticut, organized last week's bridge construction because Yawbucs Brook, which flows across the Narragansett Trail, floods periodically, making it difficult for hikers to cross. Over the years some hikers had tossed small rocks in the stream to build a makeshift bridge, but these only caused the water to dam up and spread.

Andrews decided the best solution, short of an elaborate raised span, would be to place large flat stones between the banks, spaced far enough apart for water to flow freely but close enough for hikers to step from one to the next. This is where Fogg and his trained rock workers came in.

I was invited to join the fun after having met Andrews a couple months earlier when he and I accompanied Jenna Cho and Peter Huoppi from The Day on a 23-mile day hike the length of the Narragansett Trail from Lantern Hill at the Ledyard/North Stonington border to Ashville Pond in Hopkinton, R.I.

Loyal readers may recall that I periodically chronicle my obsession with building rock walls, paths and cairns, so getting asked to be part of a project led by serious rock-movers was like a Little Leaguer being called up by the Red Sox. I also invited along my friend and neighbor, Bob Graham, who to a somewhat lesser degree shares my passion for stonework but nonetheless gets pulled in on many of my Sisyphusian projects.

Also joining last Saturday's crew were Bob Nodine, Phil Wilsey, Elizabeth "Polly" Buckley, Harry Perrine, Marlene Ewankow, the aforementioned Davidson and Fogg, and John Rek, a mountain of a man who looked like he could have moved most of those boulders with his bare hands – and in fact did so.

We assembled at the brook shortly after 9 a.m. and I was amazed to see how fast it flowed. When Andrews, Cho, Huoppi and I crossed it back in August there wasn't even a trickle. But the night before Saturday's project some 3 inches of rain poured down, and the Yawbucs took on white-water pretensions.

"It doesn't get like this more than a couple times a year," Andrews said, staring at the swirling current.

Fogg quickly took charge of the volunteers and issued various instructions, while Rek, the most experienced rock mover and technical climber who brought some of his own gear, began setting up lines. Some of us clipped branches blocking the path, others used a chain saw to cut up a 2-foot-thick tree that had fallen across the brook, and others began stringing cables. Graham, Ewankow and I began prospecting for suitable rocks with 4-foot-long pry bars.

Using the bars like levers we managed to unearth one cube-like boulder, but it proved too tippy.

Meanwhile, Fogg and the others already had skooched one huge monolith into place using a grip hoist, an ingenious contraption with hidden gears that allows one person with a moderately strong arm to move objects weighing a ton or more. It puts to shame the come-along tool I've been using for years to lug rocks.

After toiling with the equipment for a few hours Fogg finally trusted me and a couple others to rig up the lines ourselves. We first showed him the boulder we planned to move about 100 feet, and he simply said, "Go ahead – make it happen."

We then wrapped looped nylon fabric belts around two trees, attached metal hooks and chains, connected them to the cable, and positioned the grip hoist.

"Tension!" I called, warning others to stay clear of the line, and began pulling. The boulder slid slowly forward over bars we had placed like railroad tracks to reduce friction. Archimedes was right: Give me a lever and a place to stand and I will move the earth.

Twenty minutes later the boulder splashed into place.

By this time we had been laboring about six hours – all of us were muddy and tired, but happy. The bridge was finished. You can now cross from one side of Yawbucs Brook to other and not get your feet wet.

Rek the Mountain Man made a few final adjustments with his pry bar; we used the grip hoist one last time to remove the cut up logs, and tossed buckets of water over the stepping stones to wash away residual mud.

If I say so, it's a masterpiece – the Brooklyn Bridge of southeastern Connecticut. If you want to see it, hike north on the Narragansett Trail from Lantern Hill, and after passing a small body of water known as both Hewitt and Gallup Pond, cross Route 2, walk up Ryder Road, and re-enter the woods following the blue blazes on the left side of the road. Stay on the trail past the crest of Cossaduck Hill and descend to Yawbucs Brook.

If you're feeling energetic and have about 12 hours to spare, continue to Ashville Pond. Otherwise you can simply turn around – or cut it even shorter by skipping Lantern Hill and simply hiking in from Ryder Road.

I hope those who cross Yawbucs Brook, or who hike on any blue-blazed trail in Connecticut, appreciate the efforts of the CFPA and its many volunteers. I enjoyed working with the crew and am sure there will be other opportunities to pitch in on future projects.