While without a single surface spring or stream from Devil's River in the south to Yellow House Canon in the north, this great mesa is nevertheless the source of the entire stream system of central and south Texas. Absorbing thirstily every drop of moisture that falls upon its surface, from its deep bosom pours a vitalizing flood that makes fertile and has enriched an empire,--a flood without which Texas, now producing one-third of the cotton grown in the United States, would be an arid waste. Bountiful to the south and east, it is niggardly elsewhere, and only two small springs, Grierson and Mescalero, escape from its western escarpment. A driven herd normally travels only twelve to seventeen miles a day, and even less than this in the early Spring when herds usually are started. It therefore seemed a desperate undertaking to enter upon the ninety-mile "dry drive," from the head of the Concho to the Horsehead Crossing of the Pecos, wherein two-thirds of one's cattle were likely to perish for want of water. Joe Loving was the first man to venture it, and he succeeded. He traversed the Plain, fought his way up the Pecos, reached a good market, and returned home in the Autumn, bringing a load of gold and stories of hungry markets in the north that meant fortunes for Texas ranchmen. This was in 1866. It was the beginning of the great "Texas trail drive," which during the next twenty years poured six million cattle into the plains and mountains of the Northwest. Of this great industrial movement, Joe Loving was the pioneer. At this time Fort Sumner, situated on the Pecos about four hundred miles above Horsehead Crossing, was a large Government post, and the agency of the Navajo Indians, or such of them as were not on the war-path. Here, on his drive in the Summer of 1867, Loving made a contract for the delivery at the post the ensuing season of two herds of beeves. His partner in this contract was Charles Goodnight, later for many years the proprietor of the Palo Duro ranch in the Pan Handle. Loving and Goodnight were young then; they had helped to repel many a Comanche assault upon the settlements, had participated in many a bloody raid of reprisal, had more than once from the slight shelter of a buffalo-wallow successfully defended their lives, and so they entered upon their work with little thought of disaster. Beginning their round-up early in March as soon as green grass began to rise, selecting and cutting out cattle of fit age and condition, by the end of the month they reached the head of the Concho with two herds, each numbering about two thousand head. Loving was in charge of one herd and Goodnight of the other.