WAPITI, Wyo. - After the thunderstorm had passed, the sheer face of the mountain reappeared, looking strange in the evening light. I got out the field glasses and saw streams of muddy water, some of them nearly a hundred feet high, cascading down the ranks of cliffs north of us.


Soon we heard a roaring sound in the foothills above the house, and from a low rise near the stream, I was able to see the first tongue of the flood come around a bend in the channel. Its leading edge was a tumbling mass of logs and sticks, pushed by the turbulent liquid behind it. The first dark brown surge left behind it a sudden scent of wet earth, like the humus in a forest.


The load of mud was soon spewing into the clear green waters of the North Fork of the Shoshone River, itself often brown with debris carried from the higher mountains to the west. Along with all the other water courses in this area, it is doing its best to move the Rockies to the Gulf of Mexico.


Not far east of here the Shoshone River's North Fork ends in a reservoir that covers what used to be a valley of cottonwoods, hay fields, and even a small town. Old photographs of this place show ranches, roads, and a schoolhouse built of trimmed logs. In 1896, at a wedding dance where George Marquette (for whom the settlement was named) played his fiddle, nearly 50 people gathered under a sign that read Welcome.


Another photograph, taken in 1910, shortly after Shoshone Dam plugged the canyon below the town, shows a blank space of water where the buildings had been. A man-made flood is climbing the trunks of the cottonwoods, which are still leafed out. Shoshone Dam was the second federal reclamation project to be completed in the United States. Once the highest concrete structure in the world, it still irrigates many thousands of acres in Wyoming's northern Bighorn Basin, generates electricity and is a source of local pride.


But many of the people of Marquette regretted its coming. They felt they had not been paid fair value for their land, and they were bitter about being evicted. As the water rose above the trees, dead branches clutched at the dimmed and receding sun. Flocks of birds were replaced by fish, and the silt that sifted down through the water like a fine mineral snow soon buried every trace of the past.


When the lake level fell each winter, winds howled across the exposed mud flats, raising ghostlike streamers of yellow dust. It was as though the soil trapped there was restless and wanted to keep on moving.


By 1973, only 63 years after it was built, nearly one-tenth of the reservoir's capacity had been lost to this accumulation. A 65-foot pile of mud had come to rest right behind the dam, and there was no practical way to get it out. In the early 1990s this loss was more than compensated for when the structure was raised 25 feet, but the silt continues to arrive. At last count, close to 60,000 acre-feet of it - enough to form a tower an acre square and over 11 miles high - was sitting in the lake behind what is now called Buffalo Bill Dam.


The Bureau of Reclamation's Wyoming manager, John Lawson, says that raising the dam again to increase the storage volume would not be easy. As the structure gets higher, he explains, the area it submerges gets broader and shallower, so evaporation increases.


Every reservoir eventually silts up - it is only a matter of when, wrote Marc Reisner in his 1986 book, Cadillac Desert. And although Buffalo Bill Reservoir is not being destroyed as fast as some others in the West, it will probably be only a memory well before the year 3000. Except, that is, for the waterfall at its lower end.


At 350 feet, Buffalo Bill Falls will be more than twice as high as Niagara. The river will slide over the convex lip of the dam into a long whitewater confusion wreathed in clouds of spray. Ferns and moss will grow on the nearby cliffs, and during the brief periods when the sun finds its way into the canyon, a rainbow will arch across it. Once again the silt will be on its way.





Lynne Bama lives and writes in Wapiti, Wyoming.