Oak Tree Fungus? My grandfather lives right on the lake and adjectives summer I was...

My grandfather lives right on the lake and adjectives summer I was notice this weird growth on the underpinning of a large branch (what is departed of one that must have come down surrounded by a storm at some point). It is a very wan yellow color, and almost seem to look "dirty" as the weather dropped, but the last time I be up there, the "fungus" (if that's what it is) be still there. It's considerable, and doesn't resemble anything I've found on the internet. It just looks approaching someone sprayed a pale pale foam/whipped cream for about 2 and partially feet (in length) and most of the road around the entire circle of the branch.

Any ideas?
Answers:    What you are seeing is a fungi call a "conk". It is feeding on the insensible and now broken branch. Over time, as the fungi mature, it takes on a ashen yellow appearance. Many conks form at the underside of the tree trunk and some from above as you see on your grandfathers property. There are many types of conks contained by different shapes, textures, colors and sizes. Here is a connect for you to see if any of these conks match the one you are chitchat about. Hope this help.
http://www.fs.feed.us/r8/foresthealth/pub...

**Billy Ray**
Oak Wilt w/photo
http://www.treehelp.com/trees/oak/diseas...
photo below
Tree With the Fungus at Bottom
http://www.flickr.com/photos/caretta71/1...
Humongous Fungus!/photo
http://www.flickr.com/photos/85775297@N0...

Once a tree is infected, only seldom can the disease be reversed and the tree restored to health. Prevention, in opposition, has a 90% unsystematic of success. Two methods of prevention are recommended.
First, avoid pruning red oaks and live oaks during the time from mid-February through May.
http://www.northwoodhills.org/info/trees...

It is my understanding that the oak trees here within the US are being lost due to wilt/fungus probably because they shift untreated and it spreads.
Although the link above is for Texas it would apply adjectives over except maybe for the pruning time.