“Mystery tree tag on Mass. Ave”

“Dear PoPville,

On a walk this weekend I noticed a copper looking tag/plaque way up high in the tall tree in the triangle park at Mass Ave/35th St NW/Fulton St NW, just south of St Sophia’s. I’ve walked by here many, many times before and never noticed it, but the sun was hitting at just the right angle for it to flash in the corner of my eye. I thought at first it was a mylar balloon or something similar caught in the branches, but getting as close as I could it’s obviously a large metal tag or plate of some sort (about license plate size?) zip-tied to one of the boughs.

The writing is tiny and seems to be pretty detailed, but it’s at least 70-80′ off the ground! I couldn’t make out anything even from some zoomed in camera phone shots. Some light googling didn’t turn up any clues as to what it could be. Until I can get back there with some proper binoculars or a telephoto lens, does anybody have some background? I’ve never seen one like this so far out of reach (or legible reading distance!) before. First picture is what it looks like when viewed from the ground; it’s the bright object in the top half of the photo to the right of the trunk. Second is a blurry zoomed in shot, I can’t even make out any words in the title text.”