Smooth Rock Tripe

Just found some pics of greener U. mammulata (about halfway down the page): http://lichens.digitalmycology.com/macrolichens/Umbilicaria.html

It's some species of Umbilicaria. U. mammulata, smooth rock tripe, is common in your area, but this stuff looks a little too green. In your last picture, you can see that some of the lichen has a more brown upper surface, which is more typical for U. mammulata. You can check out some excellent pics here: http://www.sharnoffphotos.com/lichensG/umbilicaria_mammulata.html