It's not unusual to see moose over here (I'm back in Norway), 1, 2 or 3 of them, but I can't remember seeing 4. But it's a different species, and the social behaviour differs. I'm assuming that these were elks. That was what signs warned about. They were large (as horses), but possibly slightly smaller than European moose. Groups of deer are more common here than of moose (deer are much smaller, though, and cannot be mistaken for moose).
NIL DIFFICILE VOLENTI