Sand Hills
The Sand Hills of Nebraska is a 25,000 mi² (65,000 km²) region of plant-anchored sand dunes in the north-central part of the state. The Sand Hills were formed at the end of North America's most recent ice age by wind-blown particles originating from regions to the north and west of Nebraska. At several times in the past 10,000 years (during periods of extreme drought), the Sand Hills have been active sand dunes; however, this not happened since around 1400 CE. Dunes in the Sand Hills may exceed 330 ft (100 m) in height. The average elevation of the Sand Hills region gradually increases from about 1800 ft (600 m) in the east to about 3600 ft (900 m) in the west.
The Sand Hills sit atop the massive Ogallala Aquifer, and marshes and shallow lakes are common in the Sand Hills. The eastern and central sections of the region are drained by tributaries of the Loup River and the Niobrara River, while the western section is largely composed of small interior drainage basins. The mixed-grass prairies supported large populations of bison until the 1870s. Today, the Sand Hills is one of the most productive cattle ranching areas of the United States; ranches of 100,000 acres (400 km²) are not uncommon.
Categories: Nebraska geography