I've never experienced anything like it in my live. The wind was so strong it was almost impossible to walk, and the sand was blowing at us like bullets. We knew what direction we needed to head in, but every time we tried to face that way we were practically forced to the ground. By the time we made it back to camp we were both freaked. Don't ask me how our tent was still there...we'd left some gear in it and I guess that was the only thing keeping it from disappearing. It was still getting worse, so even though it was dark we decided to try and make the hike out. Let me tell you, without the mountains in the distance to judge by, there's no way we would have been able to make it out of there. You couldn't see, or breath, or even look up from the ground. And the thing with dunes is that there are so many ridges to cross, and the wind whips the sand up the back and over the top like a solid line of bullets. As we staggered down the back of the highest ridge, we could feel the dune literally rumbling and shacking under our feet; it was unsettling, especially since we couldn't even see the bottom. Somehow, we managed to stumble our way down to the lower dunes, and kneel down to catch our breath and try to get our bearings. In order to get back to the car, we still had to cross the creek surrounding the dunes, then head up the tree covered embankment on the far side and hopefully hit the dirt road. We took a good look at the mountains in the background and slowly kept going. I have to say I've probably never been as freaked out before...it's hard to describe how bad it really was. I was starting to wonder if the sign earlier was going to end up becoming literal.