The sand bog in Hidden Valley is awful. We last time we drove it was last December. There are hard invisible ruts hidden below the sand - more like silt. It is a messy bumpy ride. To make it worse. we watched (from camp) one long line of overlanders (10 vehicles) hit it hard at high speed and tore it up badly. The dust still hung in the air as it got dark, two hours later.
Interesting, the next night when we were overlooking Saline Valley we noticed a haze hanging over the valley. I hypothesized that it was due to the dust kicked up by all those that were passing us up. I don't think there's another plausible source of pollution, especially when the surrounding valleys were clear.
We crossed paths with two "tricked out" overland vehicles on their way out of Hidden Valley the afternoon of Thanksgiving, and we couldn't even tell their paint color due to the dust coating them. Fun?