Willet

These birds look pretty good for Willets. A few of them are showing the black wingtips and they are proportioned a little taller and slimmer than Dunlin. Their bills look dark grayish and straight, whereas a Dunlin's bill would look black and slightly downturned. Willets also have longer necks and are taller, bigger birds. It's kind of hard to tell from the photo, but it helps that I have been seeing a lot of them in the area.

Best guess is above, but I'm not sure when they exchange their drab color for breeding plumage