Myiarchus cinerascens
Later in our vacation to visit friends in Colorado, we ventured to Ridgway (about 10 miles N of Ouray). Our friends have a great deck at the front of their house, which looks out onto a hillside covered with pines. There I saw this bird flying from tree to tree. It held still long enough for this picture.
Apparently, flycatchers are a bit hard to distinguish, and I have never seen this particular bird before, and so I settled on calling this one an Ash-throated Flycatcher based on its external appearance and the location where we observed it (SW Colorado). Other close flycatcher calls are typically found too far east or too far south to be very probable sightings.