It was Alvan Buckley who asked if I had considered an Indigo Bunting.
I hadn't. It wasn't on the radar. I went back to other photos I have of Indigo Buntings to make a comparison.
While it is quite early for an Indigo Bunting to show up here (like a month early,) I actually see some blue on this bird. An Indigo Bunting has never been reported at Bidgood's Park before.
The beak is right, the coloring is right, and the size in relationship to the Yellow-bellied Flycatcher is right. (An Indigo Bunting is 5½" and a Yellow-bellied Flycatcher is 5½".)
Stranger things have happened.
There comes a time when a birder has to make the final call. I am doing that now. This is an immature Indigo Bunting. Thanks Alvan for pointing me in the right direction. This bird was located in a dead tree, across a large field on the side of the park closest to Backline Road. It was fairly close to Power's Road. On the trail opposite the field there is a sign reminding dog owners to keep their pets on a leash.
Bruce is leaning toward a Swamp Sparrow but doesn't see a perfect match for that either. The questions remain: Why is the face plain? Why are there no streaks on the back? The beak looks too long for an Indigo Bunting. Anticipating this debate, I never entered the bird into eBird. It is likely this bird will remain unidentified.