Yes - Dugway is the most commonly cited place to which Area 51 items and / or operations were (or are still being) migrated.
One place we've been a bit curious about is an Air Force flight training field outside Seguin, Texas. There have been sightings of UFOs over Seguin for many years (MUFON is headquartered there) and that training field may be the reason. But things changed around the time that the Area 51 activity was rumored to have stopped. In the old days, while driving near the field, it was extremely common to see air force jets flying low over the road. (This could by quite un-nerving if your car happened to be directly underneath the flight path at that moment) It was something one expected to see when driving in that area.
However, since the late 90's I haven't seen any air force jets flying in that area at all, and I've driven that road many, many times since. I've checked and its designation as a flight training field is still the same, and granted, I haven't been monitoring the place 24/7 so maybe I've just managed to miss every single practice flight since the late 90's - but it doesn't seem likely. And there are still reports of UFO's over Seguin...
The area is secluded*, though not anywhere near the same level of seclusion a base would have in Nevada or Utah. Still, I've had a sneaking suspicion that maybe
some of the secret activities of area 51 have been farmed out to different places, and that might be one of them. Just speculation on my part, but hey, you never know.
An odd little factoid about Dugway proving grounds is that artist Edward Gorey worked there when he was in the service. He mentioned in interviews that the place would crop up in the news every once in a while when thousands of animals would be mysteriously found dead in the surrounding area.
*ETA - I should make clear that nothing of this training area can be seen from the road. Not planes, landing strips, any kind of outbuilding, nothing. I think there are signs stating that the place is there, but as for seeing into it - nothing is visable from the road. So it's always been a bit mysterious.