It is hard to find places to hide caches in the sand dunes, but luckily there are spots other than just the dunes to put another cache for you to find.
I've had my eye on this spot for a few riding seasons and finally remembered to bring a container that will work at it.
The cache is located along what is called the "Sand Hwy" it is a stretch of level yet whoopity whoop soft sand that if using a good OHV can travel comfortably 30 to 75mph. If you use a 4wd high clearance vehicle you can drive at about 10-20mph. There are several of these Sand Hwys in the dunes. This one is used primarily for east to west travel from the "Flats" (vendor row) to as far as Gecko Rd. (Cahuilla Ranger Station). This also connects to the Sand Hwy that can get you to Oldsmobile hill.
To access this cache you can either park at the entrance Kiosk & Restrooms or over by the Glamis Beach store and make the short hike over (be sure to carry some water (even if it is the middle of the winter).
The Imperial Sand Dunes are BLM land and are regulated by the ISDRA & Park Rangers, there is a entrance fee for all primary vehicles that enter and stay for longer than a day (if you are only grabbing the nearby caches by walking you should be fine).
Present fees as of 2014-2015 season are $35 purchased offsite or online and $50 purchased onsite (Cahuilla Ranger station) for 1 week (7 consecutive days) and $150 for a season pass (valid from October 1 through April 15 each year) purchased online, offsite or onsite.
Don't forget you are in the desert and must always be aware of your surroundings. The temperatures can drop as low as the 30's and climb as high as 120+. Even though the Hwy is right nearby this location is harsh and remote, plan ahead and be safe. There is also ample wildlife please be mindful of it.