Where Are the Sand Dunes?
The Imperial Sand Dunes are the largest mass of sand dunes in California. Extending for over 45 miles in a 6 mile wide strip, the sand dunes extend from an area east of Calipatria, California southeast to the Mexican side of the border in Los Algodones, 6 miles west of Yuma, Arizona.
Where Did the Sand Dunes Come From?
Approximately 200 million years ago, this area was submerged underneath the vast Pacific ocean until tremendous earth upheavals elevated this area above the ocean. The collision of the Farallon Plate with the North American Plate pushed the Rocky Mountains up during a period of mountain building called the Laramide orogeny. This action formed the Colorado River, which at various times through its life coursed through this very area. The interior plains of the Southern California region descended, creating a basin known as the Salton Sink, where the Colorado River often times drained into Lake Cahuilla, most recently as late as 1450 A.D.
The Imperial Sand Dunes were created from the wind-blown beach sands of this vast Lake Cahuilla, where the sands have been carried from the old lakes shores to their present location. This process continues today where the winds cause the dunes to migrate at the rate of approximately one foot per year.
Note: The current Lake Cahuilla is a reservoir created in 1969 in La Quinta, California, at the southwestern edge of where its Pleistocene-era grandfather once stood.
About the Dunes
A dune is a hill of sand built by the flow of water or wind. Most dunes are longer on the windward side and have a shorter "slip face" on the leeward side, where the sand slips back down under gravity. A "dune field" is an area covered by extensive sand dunes. Large dune fields are known as "ergs."
So What Do I Need to Do?
A little on site and Internet research is required:
1. From this location, or the roads south of here, in what direction do you think the sands are migrating? There is ample evidence just by looking at the dunes themselves or the road.
2. Approximately 100 meters west of the coordinates above is a ranger station. What is the name of this station?
3. According to legend, a Spanish shipwreck is lost in the Anza-Borrego Desert, which the Imperial Sand Dunes are a part of. What was the name of either the captain of this ship or the expedition?
Optional (for fun only): Besides Star Wars VI - Return of the Jedi, can you locate any other movies that were filmed in part at the Imperial Sand Dunes? You might be amazed at the answers. Feel free to post these answers in your logs.
Email me at the link on my profile with the answers to the three questions above. You are encouraged to post a picture standing in front of or climbing the dunes, but this can not be proof of an actual visit and does not replace the email requirement.