Steven Dutch, Professor Emeritus, Natural and Applied Sciences, Universityof Wisconsin - Green Bay
Nebraska has an 80-mile stretch of Interstate that is dead straight and level.You can put a penny on the ground at the Grand Island end and read the date from Lincoln. However, once you get off the Interstate there is some surprisingly interesting scenery in Nebraska.
About a quarter of Nebraska is covered by the Sand hills, so called because the hills are entirely made of - now let's not always see the same hands - sand.Whoever said "sand" gets ten minutes of unfiltered Internet time after class. The Sand hills are Pleistocene sand dunes derived from glacial outwash eroded from the Rockies, and now (mostly) stabilized by vegetation.
The map below shows the core of the Sand hills. Note the general absence of drainage over much of the region and the numerous tiny lakes. Much of what passes for lakes in Nebraska consists of closed depressions between dunes.
Below is a representative patch of Sand hills topography. Note that some dunes are barchan-like, although they are far larger and more crowded than typical barchans. Also note the small ponds between dunes. This area is about100 km southeast of Alliance on the map above.
When you live in the Midwest, any trip west has a good chance of passing overthe Sand hills.
Barchans are crescent-shaped dunes with the horns of the crescents pointingdownwind. They are typically small, normally form where sand is sparse, and tendto be widely spaced. These dunes in the Sand hillsare crowded, obviously hadlots of sand, and are over a kilometer long, but they resemble barchans morethan anything else.
|Left and below: large barchan-like dunes. Note the small inter-dune ponds.|
|Left and below: irregular dunes with small-scale longitudinal dunes superimposed.|
|Left and below: longitudinal dunes|
|Although this looks like a sheet of clouds, it's a winter photo of the Sand hillscovered with snow.|
|Similar topography just east of the photo above. The location can be found on the maps. The three forking streams are just north of Nebraska Route 2 about halfway between Thedford and Alliance.|
|Transverse dunes with small-scale longitudinal dunes superimposed.|
|Non-oriented patch dunes.|
|Boundary of the Sand hills. Note the sharp transition to flat plains. The irrigation circles are half a mile in diameter.|
U.S. 50 in Nevada is touted as the "Loneliest Road in America," but U.S. 83 from Valentine to Thedfordcan give it some serious competition. This is an area where you get no radiostations
|All of the relief in these pictures is dune topography. Only in a few river cuts is there bedrock.|
|If you like long trains, Nebraska Route 2 is a place to see them. They are carrying coal from Wyoming, and 140 cars is not unusual.|
|Left and below: Route 2 follows one of the few drainages in the Sand hills.|
|Tiny ponds and wetlands are common between the dunes.|
|Exposures of dune sand.|
|Near Alliance the Sand hillsend very abruptly.|
|Looking northwest across flat plains.|
Above, panorama looking north from Nebraska Route 2 a few kilometers east ofAlliance, showing the edge of the Sand hills. Below, panorama looking south.
|Small tongues of the Sand hillsextend west of Alliance. Here we look south on U.S. 385 from flat plains to an outlier of the Sand hills.|
|Here we see the flat plains at right sloping up onto the dunes at left.|
|Left and below: this short strip of Sand hillsprovides as representative an example of dune topography as you can see anywhere.|
|Left and below: looking west across flat plains to the edge of the dunes. Note the sharp transition from flat plain to dunes.|
|Road cut showing Tertiary gravel. This unit underlies the dunes and is probably part of the Miocene Ogallala Group.|
|Looking off the escarpment at the edge of the Platte River valley.|
|Bedrock escarpment at the edge of the Platte River valley. This is a subdued version of the bluff topography seen farther west at Scott's Bluff.|
Created 22 July 2003, Last Update 08 June 2020