I'm not affiliated with any of those companies. But I've heard good things about Fi. True GPS collars (as opposed to blutooth) work for well over a mile. They can pretty much pinpoint your dog's location anywhere that the GPS service works. But there are a few caveats - the collar needs to be charged every X days (battery drainage depends on many factors). The collar must be on your dog and charged, and your phone must be charged, for you to track them down. There is also a yearly subscription you must pay to maintain this service.