For a few years fabulous sums of the precious metal had been extracted from the ground by the hordes of treasure-seekers who had come from all over the world by boat, pack-animal or "prairie schooner," around Cape Horn, across the Isthmus of Panama or over the western mountains. When the yield of the mines had slackened, some of the population had filtered off to newer fields, but more had settled down to exploit the agricultural and lumber resources of California. In Nevada a rich vein of silver called the "Comstock Lode" had been discovered; in 1873 a group operating the "Virginia Consolidated" mine struck the great "bonanza," and the output reached unheard of proportions. The success of the mines, however, was essential to Nevada, which had few other resources to develop, and when the yield slowed down the population growth of the state noticeably slackened. In Colorado during the late fifties some prospectors had struck gold, and another rush had made "Pike's Peak or Bust" its slogan. Some had returned, "Busted by Thunder," but others had better fortune, discovered gold, silver or lead, and helped lay the foundations of Denver and Leadville. In Idaho and Montana, in Wyoming and South Dakota and other states, prospectors found gold, silver, copper and lead, and thus attracted much of the population that later settled down to occupations which were less feverish and more reliable than mining. In general, the advance of population into the Middle West was more or less regular, as wave on wave made its way into the Mississippi Basin; in the Far West, however, population extended in long arms up the fertile valleys of Washington, Oregon and California, or was found in scattered islands where mineral wealth had been discovered in the Rocky Mountain region. From the standpoint of absolute growth, the expansion of most of the far western states was not imposing, but the relative increase was suggestive of the future. Colorado nearly quadrupled in a decade, (1870-1880), and Washington equalled the record in the following ten years. California grew faster from 1870 to 1890 than it had done in the gold days, indicating that its development was based on something more lasting than a fickle vein of ore. Meanwhile politicians were fanning the desire of the growing territories to become states, and in 1889 Montana and Washington were admitted, and in the following year Idaho and Wyoming. Of these, Washington alone had a population equivalent to the federal ratio for representation in the House.[1] Utah was kept outside for a few years longer, until the Mormon Church gave satisfactory indication that anti-polygamy laws were being enforced.