Bob, I live in west central Missouri, and I believe you could have a nesting of blues yet. In looking back at my records of 8 previous seasons, I have had a few nestings in late June & early July on occasion. It is getting a little late, but my first successful hatching of blues just fledged on this past Tuesday, so I am keeping my fingers crossed for another nest. But they have to get this batch of young ones trained yet and that could take another week or two. I will know in a few days if they are interested in building again. Bob luck – if you are seeing blues, you really need to figure out why they are not coming there. Tell us a little about your box locations. P.S. Aren’t those barn swallows a pain & messy when they like to build right outside your door, etc.