No river in the United States has been as aggressively seized for human use as the Colorado — and shelves of books have been written to tell the story. But what becomes of the river once it flows out of the U.S. and into Mexico has received considerably less print.

Now, Defenders of Wildlife has filled that gap on the shelf, providing funding for writer and photographer Charles Bergman to travel throughout the Colorado River Delta, where the river flows into the Gulf of California. The result is Red Delta: Fighting for Life at the End of the Colorado River.

It’s a heartbreaking story: Hoover Dam, completed in 1935, and Glen Canyon Dam, topped off thirty years later, strangled the Colorado River and the Delta. The 120 miles of river below the border began to disappear, and the wild Delta — which once sprawled across almost 2 million acres — has shrunk to 8 percent of its former size. The trickle coming across the border has disrupted currents in the Gulf of California as well, threatening an important nursery for blue shrimp and endangered species like the Mexican giant sea bass.

With his words and rich photographs, Bergman tells the story of the wildlife and the indigenous Cucapá Indians who call the Delta home. He also writes of the unsuccessful struggle of a coalition of Mexican and U.S. environmental groups to convince the U.S. government to provide the water needed to sustain endangered species below the border.

“We have made the desert bloom and have turned hell green,” writes Bergman — but as the noose around the Colorado gets ever tighter, the push to restore the Delta seems to be no more than a fevered dream.

Red Delta: Fighting for Life at the End of the Colorado River By Charles Bergman, 288 pages, softcover: $29.95. Fulcrum Publishing, 2002.