Take a walk along the stretch of beach where Glacier Northwest wants to excavate millions of tons of gravel over the next 40 years or so, and the debate over the proposed mine expansion becomes as clear as a bright winter day.

This is a beautiful stretch of the Island — both quiet and full of life. Eagles, cormorants, grebes and hawks abound here. Whales cruise past during the winter months. Just a stone’s throw down the beach, at Sandy Shores, a string of homes lines the beachfront road, mostly modest, cabin-like houses that have been there for years.

Juxtapose that picture with a state-of-the-art, steel pier stretching 400 feet into the Sound and sluicing sand and gravel into barges 12 hours a day, five days a week. With bulldozers working the headland above, mowing down the tangled madrone forest as it carves the hillside into huge mounds of dirt. With 192 acres — one of the largest expanses on the Island — turned over to gravel-mining.

And for what purpose? At least in part, to build more roads in Pugetopolis, a place already bursting at the seams with cars, roads, people and sprawl.

Glacier, to be sure, has its side in the argument. Despite its foreign ownership, the company has been a presence on the Island for decades. The 235 acres of land it owns is already a sand and gravel pit — albeit a small one — located on a part of the Island zoned for mining.

Perhaps most important to this publicly traded company, it makes enormous economic sense to offload gravel onto barges in Puget Sound. Such a move means it instantly bypasses the issue that vexes so many businesses on the Island — the state ferry system. The project suddenly goes from being cost-prohibitive to economical and expeditious. In fact, Glacier says, that method of mining is good for the environment: Fewer trucks traveling the Island’s byways means less fossil fuel consumption.

Sand and gravel, of course, is not bad stuff, and we all use it. What’s hard about the Glacier effort, however, is the sheer scale of it — a big-box mine on an Island where people, for the most part, live life on a modest scale. Vashon is an intimate place, and people come here, in part, to escape the madness of Pugetopolis. To have a part of the Island shaved off to feed that madness is both galling and painfully ironic.

But as those fighting Glacier point out, this is not simply a Vashon issue. At the same time that the state is granting Glacier one permit after another, it’s spending millions of dollars to restore and protect Puget Sound, an inland body that scientists increasingly say is in jeopardy. The waters that Glacier wants to work in have been declared an aquatic reserve, one of only four such designations in the state — so declared, according to the state Department of Natural Resources’ Web site, because of its “special environmental importance.”

Advocates fighting the mine say both building the giant pier and operating it could harm some of the many animals — from tiny surf smelt to the charismatic orca — that make up the web of life in Puget Sound. Ample evidence, for instance, suggests that our region’s southern resident killer whales — listed as endangered under the federal Endangered Species Act — are already struggling with the increased noise and activity in Puget Sound. A thriving barging operation, running day in and day out, will exacerbate the situation considerably.

The state Supreme Court’s decision not to hear a challenge to one of Glacier’s key permits is a setback. Considerable hope had been pinned to the high court’s ability to rein in or even halt the project. But there are still many more avenues, the most significant being the Legislature — where, just a few days into the session, four bills touching upon some aspect of Glacier’s proposed expansion are already in play.

So on the next beautiful winter day, wend your way down to Sandy Shores, slip down to the beach and take a walk on this quiet stretch of sand and cobble. And when you get home, write a letter to a lawmaker or public official, send an e-mail or write a check. This may, indeed, be one of those cases where the individual efforts of thousands of people can change the course of our region and shape the future of our Island.