This individual is in basic plumage. These photos show the lore pattern which was pointed out originally by Lars Jonsson. There is a white teardrop shaped extension forward of the supercilium which loops down in front of the eye, ending before the bill. There is also a vertical dark mark in front of the eye and a thin sub-loral loop which together form a sideways "J" mark. This mark is mentioned in the text of "National Geographic" but does not seem to be properly illustrated in the accompanying plate. I do not think this pattern is duplicated in Least Sandpiper. We only saw a few Long-toed Stints in this area.
These photos were taken from the window of the van using Canon S3 P&S.