MOST of Nevada lies within the Great Basin--a great depression whose floor is scored by numerous mountain ranges trending north-south and lying athwart the natural east-west flow of travel. With a few exceptions in the extreme northern and southern parts, all rivers draining its 110,690 square miles flow into sinks and lakes within the State. The exceptions are the Bruneau, Owyhee, and Salmon, and their tributaries, in northern Elko County, flowing into Snake River and thence into the Columbia; and the Muddy, and the Virgin, in Clark County, which flow into the Colorado. The Amargosa is in Nye County and disappears in Death Valley, California. All others lose themselves in the basin of ancient Lake Lahontan, in western Nevada, or in sandy desert wastes. The largest streams are the Humboldt, crossing northern Nevada from east to west, traversing deep gorges cut into the northsouth ranges crossing its course; in the western section the Carson, now emptying into Lahontan Reservoir; the Walker, rising like the Carson and Truckee, in California, and emptying into Walker Lake, which lies along the eastern flank of the Wassuk Range; and the Truckee, fed by Lake Tahoe and flowing into Pyramid Lake in Washoe County--at times of extreme flood some of its waters formerly found their way into the neighboring Winnemucca Lake. The major part of the Truckee's flow is diverted through a canal into Lahontan Reservoir. The Colorado River flows along the southeastern border of the State, through a series of deep and picturesque gorges.
The salts dissolved in the waters of the in-flowing streams accumulate in the lakes, or are left in the great evaporating pans called sinks, as the waters disappear. Through the ages this process had increased the alkalinity of the valley soils and created the great arid alkali flats.
The dry lakes found in large number throughout the State are vast level expanses of white sediment devoid of vegetation. The most noteworthy dry lakes, in the black Rock and Smoke Creek deserts of Humboldt and Washoe Counties, are more than one hundred miles long and from five to twenty miles wide. Northwestern Humboldt County has