I saw this olive-yellow bird creeping in the brush. I was never able to get a definitive angle.
My warbler books were not very helpful, but it is clear that the belly is almost fully white and the color is on top. The bill tells me it is a warbler since it is not barbed like a vireo. When my books do not show any clear suspects I start to look at the females.
This is the best view I have. The closest bird I can find is a female Chestnut-sided Warbler. There should be more defined wing bars but it's a pretty bird, regardless.