-
Difficulty:
-
-
Terrain:
-
Size: 
(not chosen)
Please note Use of geocaching.com services is subject to the terms and conditions
in our disclaimer.
In order to count this Earthcache as a find, you must complete the following tasks and email the answers to me.
1. Describe the landscape using the six classification terms from the description.
2. What is the elevation at ground zero?
3. Estimate the height of the dunes in the area (if present).
4. What act allowed homesteaders to claim a full section of land, rather than the quarter-section previously allowed?
This earthcache is located in the Sandhills region of Nebraska. The coordinates will take you to a historical marker near the intersection of highways US 83 and NE 2 - just east of Thedford. Enjoy!
The Nebraska Sandhills is not only the most unique physiographic feature in the state, but it is also one of the most unique areas in the world. The Sandhill region spans nearly 20,000 square miles--roughly one-fourth the size of Nebraska--making it the largest sand dune formation in the Western Hemisphere.
At the end of the last ice age (nearly 20,000 years ago), the wind took hold of the loose sand left behind and blew it into vast dunes. At the extremes, these dunes were built up to nearly 400 feet high and stretched twenty miles across the landscape. Precipitation allowed grassland plants to take root in the shifting sand, which eventually helped to stabilize the dunes and hold them in place. Since the creation of the Sandhills, major droughts in the area have resulted in less plant life and has caused more exposure of the sands to the wind. Because of this, different areas of the Sandhills region have shifted during the past several thousand years. In more recent times, the Sandhills have been carefully managed by cattle ranchers in order to preserve the stability of the dunes so that they do not revert back to a desert-like state.
The Nebraska Sandhills also rests on one of the largest aquifers in the world: the Ogallala Aquifer. The sandy soil acts like a giant sponge, soaking up rain and forming a vast underground reservoir. This aquifer consists of 1 billion acre-feet of ground water and comes above the surface at the base of many dunes. Thousands of lakes and wetlands created by this aquifer are scattered between the dry and sandy grassland dunes.
The landscape of the Sandhills can be divided into six main classifications: choppy sands, sands, sandy, sub-irrigated meadow, lakes and wetlands, and blowouts.
Choppy sands are found among dunes with steep slopes (grater than 20%). because of the steep slope, gravity causes slippage of the surface soil, exposing the underlying sand along the dune hillside and often producing what is known as “catsteps.”
The part of the Sandhills region that consists of gently rolling hills and valleys is referred to as “sands.” Dunes in this region may be nearly the same size as dunes in the choppy sands region; however, the slopes are much more gradual in the sands region than in the choppy sands.
The area that lies between the dunes, but whose soil is still composed primarily of sand, are referred to as “sandy” range sites. The landscape here is flat as a pancake with slopes of less than 3%.
The area located between the dunes where groundwater is close enough to the surface to allow plant roots to reach it is known as the sub-irrigated meadow region. The constant water supply allows a significant amount more of plants to grow in this area--and much more abundantly. Because of the rich vegetation, the sub-irrigated meadow region serves as a good area for cattle-grazing and are usually hayed by ranchers during the summer.
The Nebraska Sandhills, known for its arid sand dunes, is also a region of water. Thousands of lakes and tens of thousands of wetlands are scattered throughout this region. They range from small ponds that dry up in the summer to reservoirs that stretch for miles. The majority of lakes in the Sandhills are very shallow and average around ten acres or less in area. The reason why the Sandhills region is dotted with water is because it sits on top of the Ogallala Aquifer--one of the largest aquifers in the world containing an estimated 1 billion acre/feet of water. In the Sandhills region, little of the precipitation runs into streams and rivers. Instead, most of the water percolates, or filters gradually through a porous surface. In this case, the water filters through the sand, quickly recharging the groundwater. Lakes form between dunes; wherever the land’s elevation dips below the level of the water table, it is filled by groundwater. The number and size of lakes in the Sandhills a year depend upon the amount of precipitation each year.
The last area of the Nebraska Sandhills is known as the blowout area. Blowouts are sandy areas where rapid wind erosion literally “blows out” a hole in the surface of the landscape. Blowout are found scattered throughout all of the Sandhills and vary in size. They may be anywhere from a few feet in circumference to a few hundred feet. Blowouts usually occur in areas where plants and their stabilizing roots become depleted, exposing the sandy soil to the wind. The blowout will expand as the wind continually blows, deepening and widening the hole and covering over surrounding vegetation. These conditions make it difficult for most plants to establish themselves in a blowout. A few species, however, such as the Sandhill Muhly (a grass), thrive in blowouts. These plants work to stabilize the soil and allow for more plants to establish themselves in the blowouts. Over many years, the blowout is completely stabilized again and returns to its typical sandhill prairie state.
The Sandhills were long considered “an irreclaimable desert.” The sandy soil makes the area unsuitable for cultivation. In the late 1870s and again in the 1890s, there were many unsuccessful attempts at farming. Although farming failed in this region, cattlemen discovered the Sandhills‘ potential as range land and began to establish huge ranches in the area. Many ranches still exist in this area today, but none are as large as those of the past.
Resources:
Unstad, Kody. "Sandhill Landscape." The Nebraska Sandhills. Web. 12 Sept. 2010.
NOT A LOGGING REQUIREMENT: Feel free to post pictures of your group at the area or the area itself - I love looking at the pictures.
Additional Hints
(No hints available.)