B13: Horseshoe Lake EarthCache
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Difficulty:
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Terrain:
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Size: 
(large)
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The oxbow lake located in McBride is an abandoned meander of the Fraser River.
Now cut off from the Fraser River, Horseshoe Lake is considered an oxbow lake. The length of the lake, along the horseshoe, is approximately 1.9 km, with the widest part of the lake about 200 meters.
To log this earthcache, you are going to have to e-mail me the answers to the following questions and post the optional photo.
Information for the questions can be found on the cache page, and at the Earth Cache location.
The posted coordinates will take you to an observation platform and gazebo and this is where you will be able to find the answers to some of the questions below.
1) What is the approximate width of the oxbow lake at the posted coordinates? (This type of question is used to prove that you actually visited the cache location)
2) What is a cut-off? (answer can be found by reading the cache page)
3) Do you see any evidence at the location that the oxbow is slowly being lost to the forces of nature? Please explain your answer whether yes or no.
4) What direction would the water have flowed when this was still part of the Fraser River?
5) (Optional) This is a great location for bird watching. Can you name any of the species of birds you may have seen while at the location?
6) (Optional) Take a photo of yourself with the oxbow and submit it when you log the Earth Cache so that others can enjoy
You do not have to wait for permission to log the Earth Cache, log it after you send me your answers and I will get back to you if there is a problem with your answers.
Formation of an Oxbow Lake
When a river reaches a low-lying plain, often in its final course to the sea or a lake, it will meander widely. An oxbow lake is formed when a river produces a meander (or curve), due to the river eroding the banks. As the river begins to curve, it cuts and erodes into the outside of the curve and deposits sediment on the inside of the curve. This is due to the fact that the stream moves more rapidly on the outside of the curve and more slowly on the inside of the curve. Thus, as the erosion and deposition continues, the curve becomes larger and more circular.
Eventually,the meander becomes very curved, producing a neck where the two portions of the river almost touch. As the river neck becomes very narrow, the river can break through, this produces a new straighter channel and an abandoned meander loop, called a cut-off. For a short time, water flows both around the meander and through the new channel simultaneously.
As water will take the path of least resistance, eventually the river cuts off the backwater completely by filling the openings to the cutoff with sediment as the water flows through the newly formed channel, this results in the formation of an oxbow lake. This process can occur over a time scale from a few years to several decades.
The oxbow lake lasts until it becomes overgrown with weeds and debris, and filled in with soil, as there is no longer current to move sediment and debris along.
Interesting Fact:
It is called an oxbow lake because it is shaped like a yoke that was once used to hitch an ox to a plough.
Information Sources
http://en.wikipedia.org/wiki/Oxbow_lake
http://www.travel-british-columbia.com/north-bc/yellowhead-highway/mcbride/
http://www.trailpeak.com/trail-Horseshoe-lake-near-McBride-BC-3058
FV
Additional Hints
(No hints available.)