It is a Cecropia Moth. It is the largest moth in North America with a wing span of 5-6 inches. It is a member of the Giant Silk Moth family (Saturniidae). The female often lays her eggs on Maple, Cherry, Plum, Apple, Elderberry, Willow, Birch or Boxelder trees, where the caterpillars eat and grow fat until fall when they make their cocoon. The moth stays in the cocoon all winter until next spring when the cycle starts all over.
We concluded that we were looking at a female, because her body was very big and round. The male Cecropia has a thinner more angular body. After we took our pictures and looked at the moth closely, we took her out and tucked her into a tree. Hopefully, she found a place to lay her eggs so will can see more Cecropia moths next year.
Isaac's nature page