I was looking at/around Fort Irwin, CA when I came across this. It is around 3020ft long. It is unclear to me if this is still there. On google maps, this looks like an empty airstrip.
I looked up this phrase and found the article included here:
The artist group behind this, Indecline, claims that it is the "World's Largest Illegal Graffiti." Interestingly, it appears to have been partially covered up since it was done in 2015.