5th and Harvard St, NW on the Reservoir side
I noticed this a while back while running around the McMillan Reservoir.
Do you have any clue what I presume this memorial in a tree is about? So odd!”
The reader then answered their own question finding this 2005 post from DCist:
There stands a tree — the middlemost tree, in the photo above, sans leaves — and to it is nailed or otherwise affixed a small bronze plaque dedicated to the memory of … well, in the time since it was placed there, the tree has grown around it. “UIS ALBERTO VASQUEZ,” to be sure. And whatever it was happened in mid-1997.
Sometime during the early morning hours of the May 9, an intoxicated 26-year-old Maryland man, Alberto Vasquez, lost control of his Volvo on Harvard Street NW and struck a tree. With him in the car was Louis Alberto Vasquez, his 27-year-old cousin, who died on the scene.
Today you can see the plaque is almost completely swallowed up by the tree.