| Sand Hills | |
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Sand Hills in Hooker County, near sunset in October
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| Country | United States |
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| State | Nebraska |
| Part of | Great Plains, High Plains |
| Rivers | Niobrara River, Snake River, North Loup River, Middle Loup River, Dismal River |
| Area | 19,600 sq mi (50,764 km2) |
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The Sand Hills cover portions of northern and western Nebraska.
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The Sand Hills, often written Sandhills, is a region of mixed-grass prairie on grass-stabilized sand dunes in north-central Nebraska, covering just over one quarter of the state. The region is variously defined by different organizations, so its size is indicated as 19,600 mi² (50,760 km²)[1] or 23,600 mi² (61,100 km²).[2]
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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 1,800 ft (550 m) in the east to about 3,600 ft (1,100 m) in the west.
The Sand Hills sit atop the massive Ogallala Aquifer; thus both temporary and permanent shallow lakes are common in low-lying valleys between the grass-stabilized dunes prevalent 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 World Wide Fund for Nature (WWF) designated the Sand Hills as an ecoregion, distinct from other grasslands of the Great Plains. According to their assessment, as much as 85% of the Sand Hills ecoregion is intact natural habitat, the highest level in the Great Plains. This is chiefly due to the lack of crop production: most of the Sand Hills land has never been plowed.[2]
Paleoclimate proxy data and computer simulations reveal that the Nebraska Sand Hills likely had active sand dunes as recently as the Medieval Warm Period, when global temperatures were about 1°C (1.8°F) warmer than the current climate. Much of the area was a scrub desert, with desert-like conditions extending to several other states.[3][4] Current global warming may make the grassland climate more unstable, giving way to desert given more fires, mild drought and erosion; UCAR simulations based on evapotranspiration support a Palmer Drought Index lower than -15, many times more severe than Texas during the Dust Bowl.[5]
The plant-anchored dunes of the Sand Hills were long considered an irreclaimable desert. In the 1870s, cattlemen began to discover their potential as rangeland for longhorn cattle.
The fragility of the sandy soil makes the area unsuitable for cultivation of crops. Unsuccessful attempts at farming were made in the Sand Hills region in the late 1870s and again around 1890. Some development of cropland agriculture in the modern era has occurred through the use of center-pivot irrigation systems.
The 1904 Kinkaid Act allowed homesteaders to claim 640 acres (2.6 km²) of land, rather than the 160 acres (0.6 km²) allowed by the 1862 Homestead Act.[6] Nearly nine million acres (36,000 km²) were successfully claimed by "Kinkaiders" between 1910 and 1917. Some of the Kinkaiders attempted to farm, but these attempts generally failed. This included Nebraska's largest black settlement, DeWitty, which was located in southeast Cherry County until the 1930s. Many of the largest ranches broke up about the same time due to regulations against fencing federal range lands.
Today, the Sand Hills are a productive cattle ranching area, supporting over 530,000 beef cattle. The population of the region continues to decline as older generations die out and as younger generations move to the cities. However, there are still a number of small towns in the region that celebrate both their cultural heritage and their physical location.
As the largest and most intricate wetland ecosystem in the United States, the Sand Hills contain a large array of plant and animal life.[1] Minimal crop production has led to limited land fragmentation; the resulting extensive and continuous habitat for plant and animal species has largely preserved the biodiversity of the area.
The Sand Hills are home to 314 vertebrate species including mule deer, coyotes, red fox, meadowlarks, wild turkeys, native bat species and many fish species.
The Sand Hills' thousands of ponds and lakes replenish the Ogallala Aquifer, which feeds creeks and rivers such as the Niobrara and Loup rivers. These bodies of water are homes for many species of fish. The lakes are mainly sandy-bottomed and provide water for the region's cattle, as well as a habitat for aquatic species. However, some lakes in the area are alkaline and support several species of phyllopod shrimp.
720 different species of plants are found in the Sand Hills. Of these, the majority are native, with only 7% exotics — half the percentage of most other prairie systems. The blowout penstemon (Penstemon haydenii) is an endangered species, found only in the Sand Hills and in similar environments in central Wyoming.[7] The blowout penstemon stabilizes the soil where wind erosion exposes the bare sand and creates a blowout, but is choked out when other species begin to recolonize. Grazing and land management practices used by Sand Hills ranchers have reduced erosion, thus diminishing the plant's habitat.
Many of the plants of the Sand Hills are sand-tolerant species from short-grass, mixed-grass and tallgrass prairies; plants from all three of these can be found within the Sand Hills ecosystem. These plants have helped to stabilize the sand dunes, creating an ecosystem beneficial for other plants and animals. Better land management and grazing practices by the ranchers of the Sand Hills have led to less erosion over time, which has kept the natural landscape of the Sand Hills mostly intact.
Many species of insect are found in the Sand Hills, including dragonflies, grasshoppers and mosquitos. There are also many types of spider. Due to the ephemeral nature of both alkaline and freshwater lakes throughout the region, coupled with the wetland marsh areas, mosquito populations increase during the summer months.
The Sand Hills are part of the central flyway for many species of migratory birds, and the region's many bodies of water give them places to rest. The ponds and lakes of the region are lay-over points for migratory cranes, geese, and many species of ducks. Species found year-round include the Western Meadowlark, the state bird of Nebraska.
The Sand Hills is classified as a semi-arid region, with average annual rainfall varying from 23 inches (580 mm) in the east to less than 17 inches (430 mm) of rain in the west. Temperatures range from lows of −30 °F (−34 °C) to highs of 100 °F (38 °C).
Valentine National Wildlife Refuge, located about 20 miles (32 km) south of Valentine, covers 19,131 acres (77.42 km²). Crescent Lake National Wildlife Refuge in the central Panhandle covers 46,000 acres (175 km²). The Nature Conservancy's Niobrara Valley Preserve in Cherry, Brown, and Keya Paha counties covers 60,000 acres (202 km²) and includes a 25-mile (40 km) stretch of the river. Fort Niobrara National Wildlife Refuge near Valentine covers 19,000 acres (77 km²). Partnering in the effort to conserve the Sand Hills are: Institute of Agriculture and Natural Resources, West Central Research and Extension Station, The Nature Conservancy of Nebraska, Natural Resources Conservation Service, Nebraska Natural Heritage Program, University of Nebraska, and the United States Fish and Wildlife Service.
Bleed, Ann (1990). An Atlas of the Sand Hills. New York: Conservation and Survey Division, University of Nebraska at Lincoln. ISBN 156161002X.
Jones, Stephen (2000). The Last Prairie. Camden Maine: Ragged Mountain Press McGraw Hill. ISBN 007135347X.
