I have several sizeable green spaces I use for running the dogs.
One is a golf course built on 160 acres. In the summer I'm out there almost every weekday morning. I walk or run, and the dogs are off leash. I do this when it's light enough for me to keep track of them but there are no golfers out there. The course is 90% walled/fenced in, so there isn't much risk. They learn pretty quickly to ignore the greens keeping crews.
Another is the undeveloped part of a cemetary. It's probably 40 acres and it's planted to brome. I use it less frequently--more for weekend runs. When they're young it's a great place to teach them to keep track of me. They'll be ranging out in front of me and I'll make a sharp turn without saying anything (90 degrees or more). They learn pretty quick to watch me.
Then there are a couple of "parks" that have baseball fields. We use these to play fetch. Again, early in the morning there is seldom conflict with baseball. They're also 90+% fenced in, reducing risk. One of these spots has some undeveloped ground towards the back that was the fallout area for some now-decommissioned trap and skeet fields. We sometimes go out there and walk or play fetch. The grass is a little taller there, which forces them to mark a little better and use their noses to find the dummy. Playing fetch at these places isn't training; retrieving the ball or dummy is just a way to get a good work out for the dogs in a limited amount of space, and they to really have fun.
None of these places are "officially" for running or training dogs, but I've encountered grounds keepers at all of them and they've never said a word.
