In answer to Ruth's question Black Terns are regularly seen at the Missisquoi NWR in Swanton. I visited the refuge a week or so ago and saw four Black Terns at Charcoal Creek. An added benefit to visiting Swanton is that you can easily see Poposquash Island and its nesting Common Terns from Lower Newton Road in West Swanton. If that is not incentive enough you can visit the Franklin County Airport for Grasshopper Sparrows and Vesper Sparrows.
I have seen Upland Sandpipers in nearby Highgate in past years, but have not visited there this year. Perhaps others will share their experience finding Upland Sandpipers before these birds leave Vermont in July.