Lake Pelican EarthCache
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In order to count this Earthcache as a find, you must complete the following task and email the answers to me.
1. Describe the area around Lake Pelican.
2. Estimate the size of the ice chunk that sat in this area 12,000 years ago.
3. What benefits might a watershed provide to a community?
4. Name two of the things the Upper Big Sioux River Watershed Project does.
This Earthcache is located at Lake Pelican, a product of the glacial activity that passed through the area 20,000 years ago. This area used to function as a small campground site, but is now mainly used for shore fishing, boat launching, and sometimes even swimming. There are several traditional caches in the area as well. Enjoy!
As you may have guessed, the lakes in the Glacial Lakes region all have their origins in melted glaciers. The last glaciers to retreat from this area of South Dakota left about 12,000 years ago. As the glaciers retreated and began to melt, chunks of ice broke off from the main ice sheet. Several of these ice blocks became trapped by glacial debris that had been left behind as the massive main ice sheet worked its way across the area. Because the build up of glacial debris blocked the way for the ice chunks that broke off, they were forced to sit and melt. The sheer weight of these stagnant ice chunks created depressions in the earth. As the earth began to warm and the ice block began to melt, the depressions filled in with water--largely glacial melt water--and a lake was born. Lake Pelican is an example of a lake created by a piece of ice that broke off from the main ice sheet and was forced to sit as it melted. If you look around the area surrounding Lake Pelican--particularly to the west--you will notice several hills dotted with large boulders. These hills are piles of glacial debris that were pushed up as the main ice sheet moved across the land. The boulders are larger, much more compacted examples of glacial debris that were left behind.
Lake Pelican also lies within the Upper Big Sioux Watershed. A watershed refers to an area of land where water from rain and melting snow or ice drains downhill into a body of water, which is connected to other water channels, and eventually ends up draining into a main waterway and carried to the Gulf of Mexico or the Hudson Bay depending on which side of the continental divide you are on. In the case of Lake Pelican, the main waterway would eventually carry the water into the Gulf of Mexico. If you picture a tree with branches and limbs stemming off from the trunk or veins coursing through your body, you have a pretty good visual of what a watershed district looks like.
The Upper Big Sioux Watershed is the second largest in eastern South Dakota. The water from Lake Pelican flows out to the Big Sioux River, which then drains into the Missouri River, which drains into the Mississippi River, which ultimately drains into the Gulf of Mexico.
Pollution has been an issue in the watershed, but the problem is getting better because of preventative measures. Phosphorus and sediment--the two major pollutants in the watershed--can be found in large amounts in Lake Pelican. The Big Sioux River has been identified as the middle-man culprit for these pollutants.
Throughout the year--particularly in the spring--high concentrations of nutrients and solids from feeding operations, grazing lands, and row-crops find their way into the Big Sioux River. Livestock access to its stream banks and the use of pesticides that remove plants from the river also add to the pollutants carried away by the Big Sioux River. Some of these pollutants are then carried and dumped into Lake Pelican. This causes elevated phosphorus levels in the lake, which fosters algae blooms, and adds to the poor water quality of the lake. To combat the pollution problem, the Upper Big Sioux Watershed Project has been created to help lessen the amount pollution in the Watershed (including Lake Pelican) and to help lessen the pollution already in the watershed.
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.
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