To the left of the boardwalk just before the main observation deck in the large bare tree and neighboring trees, I saw a bird grayish above, bright yellow lower stomach with constrasting white in throat, and white sides to the tail feathers.  I did not get a good enough look at the head and bill with binoculars and have come home to get my scope and tripod, which should have been in my trunk.  Any other possibilities for what it could be?

Tom Jones
Washington, D.C.