Number of red lights flying slowly across sky

Let dog out and saw large number of reddish lights moving east to west. They moved slowly over a large park up a hill from my house.  There was no discernible sound. I called my husband out and he counted a total of 23 lights in the sky.  Most were in 2 main groups. A couple followed by themselves.  The lights moved behind a tree and as I moved to continue to watch the lights they were gone.  Single lights contined to appear from what seemed like one place in the sky.  The single lights were moving in a line across the sky.   They seemed to reach some point and were gone.  There would be a short break where I could see no lights.  Then a light would appear and 2 or 3 more would follow in a line. Then there would be a short break again and it would start again.  My  husband stopped watching when the large groups were gone.  I contined to watch and walk around for 15 minutes or so.  When I came in the single lights continued.  We were going to go up to the park but t! he lights were gone when I checked 15 minutes later.
We are near Ft. Drum, so could be something military.  However, no sound so not helicopters.  Seems like an awful lot of drones.  I don't know if drones make noise.  No reports in the media of the lights.
My husband and I are both professionals.  Never have seen anything like this before.  I took pictures of the lights -- don't show much, except 10 lights in the sky.