I step into the painting of the four blue horses.
I am not even surprised that I can do this.

One of the horses walks toward me. 
His blue nose noses me lightly.  I put my arm 
over his blue mane, not holding on, just
commingling.
He allows me my pleasure.
Franz Marc died a young man, shrapnel in his brain.
I would rather die than try to explain to the blue horses
what war is.
They would either faint in horror, or simply
find it impossible to believe.
I do not know how to thank you, Franz Marc.
Maybe our world will grow kinder eventually.
Maybe the desire to make something beautiful
is the piece of God that is inside each of us.
Now all four horses have come closer,
are bending their faces toward me
as if they have secrets to tell.
I don't expect them to speak, and they don't.
If being so beautiful isn't enough, what
could they possible say?

("Franz Marc's Blue Horses", Mary Oliver, in Blue Horses 2014)

This is Franz Marc’s Tower of Blue Horses. It is the picture on the cover of Mary Oliver’s book, Blue Horses, so I believe it is the work that she wrote the poem about. I retrieved the image from FranzMarc.org. I don’t know much about Franz Marc, but I think it would have made him happy to know Mary Oliver appreciated his work and wrote about it so that her readers could know about him too. How special, that she would pay such a great tribute to this artist who died so young in World War I.