wow i saw some of these on a bush in the mountians but never this many, the last time i saw that many bugs at once the whole forest was covered with ladybugs, trees, rocks, leafs, plants, ground it was crazy.
That makes your eyes drop out, amazing. and a little frightening, so those are elder bugs, they really do look like milkweed bugs, now i will have to go and check what the milkweed bugs i found were on, perhaps it was box elder . Amazing picture, do you know if they smell by any chance?
These bugs are on a jupiter tree and some more on the elder tree right behind the jupiter. To look at it from a distance, it looks like the tree is bleeding.
Here is a wider view for purposes of demonstration. The "piles" of these bugs are thick, as shown in the first image and they are also on the ground and on the backside of the trees. They also extend up the tree. There were more of them earlier today.