Sigh... :) They're going back south and we happen to run into a few. I suspect some are juveniles/immature and this is really throwing me off. Western Sandpipers were seen in this area a few days ago, but none of these look quite right for that.
I am looking at the eye line and I get three possibilities: semipalmated, western, or white-rumped, in roughly that order. I am not sure about second photo - the bill appears a different color. And one of the birds in the 4th photo may not have the eyeline.