Location should be Cassin's but it looks much more like a Blue-headed way out of range. Besides the great amount of yellowish wash, the distinct border of the dark head and white throat, which it typically a blurred line on a Cassin's. The contrast of the dark head and the yellowish-green back also suggest Blue-headed, over Cassin's. The yellowish flanks and vent strap also suggest Blue-headed. Challenging ID. Now awaiting input from other experienced birders who were contacted and given images of this bird for the ideas on the ID of this bird.