Shields, castles, mottos, and mustangs adorn a mound of stones in the Mojave Desert.

The pile of painted rocks represents United States Army units from various locations. They stand against an otherwise empty landscape (even the base is about six miles down the road).

The pile is next to the main gate of the Fort Irwin National Training Center. The boulders feature the insignias of the units who have trained there. Command Sergeant Major Victor Martinez calls them “symbols of pride and allegiance,” and it’s become a tradition to paint them on the rocks to mark the end of a unit’s tenure.

Many of the rocks change from year to year, but some have remained the same. The current oldest insignia is an alligator representing Fort Hood, Texas.