If you were to quickly drive through downtown Big Spring, you might mistake it for yet another gritty West Texas outpost bypassed, literally and figuratively, by Eisenhower’s vaunted Interstate Highway System. More than a few of the stately old buildings seem to have waved the white flag of surrender, their missing windows an invitation to shelter-seeking pigeons. Like many others, this town of roughly 22,000 souls is not immune to the rising and falling fortunes that come from hitching one’s wagon to the volatile Texas trio of ranching, railroading, and roughnecking. But overlooking this place means dismissing its significance as a gateway to the American West, a status born of that rarest of things: fresh water at the edge of the Chihuahuan Desert. The fount that…