Mountain News: 

Dust in the wind, stories in the snow

SILVERTON, Colo. — Are cattle grazing in Arizona causing snow near Silverton, Crested Butte and Aspen to melt more rapidly during spring? That interesting line of conjecture was submitted at a recent meeting of geographers held in Denver.

Everybody who skis the backcountry or who has dug a "hasty pit" to study the stability of a snowpack has seen layers of dust left by winter storms. The dust can look like the layers of frosting in a cake.

Thomas Painter, a research scientist at the National Snow and Ice Data Center, said that as the snow melts, the exposed dust layer forms a dark surface crust, somewhat like a dirty roadside snowbank. This crust soaks up nearly twice as much sunlight as uncontaminated snow.

Computer models predict the dirty snow melts 18 days earlier than white snow, although that has not yet been proved, a scientist told the Rocky Mountain News.

Six of seven dust storms in the San Juans and Elk Mountains studied by Painter’s team were traced to northeastern Arizona, mainly to grazing lands on the Navajo Reservation. Painter blames cattle grazing. He further points to tubes of sediment from the bottom of mountain lakes in southwestern Colorado that indicate the red desert dust began flowing into Colorado 150 years ago. Cattle began proliferating in the Four Corners region about the same time, he said.

Or did they? Sheep are more common than cattle, and in any event, livestock grazing probably did not begin until somewhat later. However, a regional event called the Little Ice Age, which was at a time of wetter and colder weather, ended about 150 years ago.

But why does any of this matter? Well, if temperatures warm in the West, conditions may become drier. If they are drier, that means more dust – and more dust means snow disappears more rapidly in the San Juans.

If snow disappears more rapidly, then the bare ground will soak up and absorb heat more readily, further increasing the temperature – and in turn affecting local vegetation, from trees to alpine wildflowers. And if the vegetation changes, then the animals that browse them will… Well, you get the idea.

Steamboat’s aging population

STEAMBOAT SPRINGS, Colo. — The greying of ski towns across the West would be a surprise only to Rip Van Winkle. Through the 1990s, the biggest jump in proportionate population growth rates in Breckenridge, Vail, and many other places was in the 60-plus age bracket. Younger people were still more common, but they ceased being the overwhelming majority.

Now, in the new century, the bulge is becoming even more conspicuous as baby boomers within ski towns get ever more grey hair while baby boomers from elsewhere begin to retire to ski towns. This trend is being noted in Steamboat Springs, where the retirement-age population is increasing at a rate six times the national average.

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