Tanks for the warning

In our travels, we've passed road signs advising us about farm machinery, trucks, various wild animals, livestock, blowing dust, flash floods and prisons, but this was the first one with an image of a tank. The sign is in the U.S. Army's Yuma Proving Ground on the Imperial Dam Road north of Yuma, in a dusty, sandy training area. The Bureau of Land Management's Imperial Dam Long Term Visitor Area is just down the road.