This mineral deposit (thought it was fossil) is in the support of the Illinois Central 14th Street Railroad Bridge in Clarksville, Indiana near the Falls of the Ohio State Park.
This the last picture I took at the bridge and it looks like some sort of coral. It has this neat white residue that looks like salt or something on it. I am guessing it is been weathering since the bridge was built in 1868 so its been exposed for a long time.
After consulting the naturalist as the nearby Falls of the Ohio State Park he told me it was calcium carbonate (travertine).