For many people who lived through the 1930's, that decade's most potent symbol was the Dust Bowl. No one forgets a legendary drought or dust storms of biblical proportion. Now in the heart of the American West, people are harking back to what their parents or grandparents saw in the 30's because they're seeing a version of it themselves today. Much of the West, and especially the region running from eastern Montana south through the High Plains, is entering its fourth straight year of drought, and in places the dust has begun to blow again. This feels ominous to almost everyone who experiences it, even though there is little likelihood of a dust bowl like the one the 1930's saw. Agricultural practices have changed radically since then, and marginal farmland has been taken out of production and restored to grass. But a drought of this magnitude broadens the meaning of the word marginal. Suddenly, for instance, wheat farming in southeastern Colorado looks almost improbable, dependent as it is on more rain than the region has been getting in the past few years. Dust in the air is a sign of exposed topsoil, as well as prolonged drought, and nothing exposes topsoil faster than the repeated failure of crops that can't adapt to aridity. In "Bad Land," Jonathan Raban wrote about early-20th-century settlers who came to eastern Montana, lured by railroad promotions promising a farmer's paradise. Those settlers were caught in a pattern that is now too familiar - a succession of wet years that causes an expansion in farmland and livestock herds followed by a succession of dry years that causes a sharp retraction. Those early settlers moved west because they were led to believe there would normally be enough water. What we know now is that "normal" may also mean times when the thought of enough water even to grow wheat looks like a mirage.:
