IN 1989, landscape photographer Frank Gohlke began a journey exploring the Sudbury River's reservoirs, swamps, marshes, and meadows. Mr. Gohlke had moved to the Sudbury Valley about 15 miles west of Boston in 1987.
For three years, he trekked along its banks or glided down it by canoe, chronicling the river as it changed with the seasons. Now 50 of the 700 color images he took are on display at the DeCordova Museum in Lincoln, Mass. The exhibition, called ``Living Water,'' captures the river at its most beautiful - and where it is most threatened.
The Sudbury River system winds 40 miles through several towns and conservation areas. Henry David Thoreau, Ralph Waldo Emerson, and others lived near its banks and wrote about it.
Today, the river - like many in the United States (see list, left) - is threatened on several fronts. Its shores and land nearby have been a magnet for developers. The river's sediment is laced with mercury from a factory that dumped dye in the early part of this century, and it is therefore unsafe to eat the fish. Other types of pollution from runoff trickle into the water.
Still, the Sudbury is in relatively good condition because of preservation efforts by the Sudbury Valley Trustees, a local land trust that has purchased many acres for conservation.
Gohlke, who has taken photographs of Mount St. Helens after its volcanic eruption, as well as landscapes of the American South and Midwest, has exhibited in a number of museums, including the Museum of Modern Art in New York. During his time spent photographing the Sudbury River, Gohlke says he became more aware of the fragile balance between human beings and the environment.
``I got a much clearer sense than I ever have of all the forces at work in creating the landscape that we live in - both the forces working for its preservation and the forces that are unconcerned with those issues,'' he says.
``It's really crucial to pay the same kind of attention and give the same kind of honor to our immediate surroundings as it is to the great glories of our national landscape,'' he says. ``A little river like the Sudbury is as much a part of that glory as the Grand Canyon.''
* `Living Water' runs from Sept. 25 through Nov. 28.