The Rio Grande surged from northwest to southeast for three thousand kilometers, crisscrossing more than half of central and northwestern North America. Along both banks of this fifth-longest river in North America, its many branching water systems stretched outward, flowing through and nourishing hundreds of thousands of square kilometers of grassland, millions upon millions of bison and wild deer, and hundreds, even thousands, of nomadic hunting tribes large and small.
To the Coahuiltec tribes at its lowest reaches, it was the motherlike "Bravo River." To the Concho tribes a little farther upstream, it was the "Concho River" that had given birth to their people. And the long two-thousand-kilometer course along the lower reaches of this great river was precisely the natural border that, in later generations, would divide the United States and Mexico.
Along this later "borderline," the most famous thing was endless black gold, industrial blood in astonishing reserves—shallow oil and natural gas! Of course, in this era, so-called "shallow" oil was still several hundred meters deep, beyond the reach of the world before the Industrial Revolution. However, geological sedimentary zones rich in oil naturally would not lack coal either. In fact, enormous coal belts numbering in the tens of billions of tons lay exposed or shallowly piled on both sides of the lower Rio Grande water system, waiting for the day someone would seek them out and dig them free...
When the Red Crow Tribe swept across both banks of the great river and gathered together a hunting-tribe alliance of astonishing, unprecedented scale, the two most serious problems on the Northern Continent were laid before the chieftain of the tribal alliance: fuel and food!
Without fuel, tens of thousands of gathered tribespeople would not survive the terrible Cold Wave; their population might very well be cut in half