The bird was discovered by Gib, the owner of the house with all the feeders. 

The Yellow Grosbeak would perch on the Cottonwoods at the back of the property near the ravine and water. It would come into his sunflower seed feeders, both hanging and flat near the back porch. The bird never sang while I was present. It did call a few times which I recorded and will upload to this report.

The bird was large (bigger than an American Robin but smaller than an American Crow), chunky (typical of other grosbeak species), and thick seed bill (dark silver to medium gray). It was all bright lemon yellow except the worn black wings, tail and legs. The vent was clean white. The wings also had two white wing bars and white primary coverts. The white flash of the primary coverts was obvious when flying. I did notice some white on the tail corners. It was visible only for a split second when landing. The underwing coverts were dull yellow with the primaries and secondaries dark gray to black.

 The bird had obvious worn feathers on the wings with all the white tips fraying. I did notice from my photos that several black feathers, one on the wing and two on the covert had been molted recently. This is what tiped me off that the bird might be an immature molting into adult plumage. Also noted that the bird had fine brown streaks. One was a post ocular stripe, one was a lateral crown stripe, the rear auricular patch and nape. These also tipped me off to a possible immature.