There were 20 objects in 5 different formations/groups, containing 5,5,4,3, and 3 respectively
This event was seen by myself roughly over the Snake River at Twin Falls, Idaho, observed from the Visitor Information Center looking north. Although there were other people nearby, none other than my spouse seemed to notice what we saw. It was a bright daym temperature 84 degrees, with a slight breeze, the sky was blue with some wispy clouds.
The objects appeared suddenly in the east sky, in formations of 5,5,4,3, and 3 craft each, moving at what appeared to be a very slow but unknown speed. They made no audible noise whatsoever, at any time. All of them moved at consistant pace, and were on a west bound flight path. However, several but not all of the objects appeared to wobble at different moments; those which did this also relected sunlight (?) when they moved that way. In addition, the objects changed the shape of their respective formations in a deliberate manner, both chevron and diamond shaped patterns were observed by myself.
This sighting lasted approximately 10-15 minutes. All of the objects disappeared abruptly, in the same way they appeared, as if into thin air.