Using this data
Everything published here is free to cite, quote and reproduce, including in commercial work, provided you link to the page you took it from. No permission needed and no need to ask first.
Each study states its method and its limits on the page. The headline one is that our park records cover the parks we list, which is not every off-leash area in a city, and we say so rather than implying national completeness.
Writing something and need a cut we have not published, a city that is not in a table, or the underlying rows in another format? Ask, and we will send it.
How the record is built
Park attributes are only published once a source has established them, and each one carries where it came from. Where nobody has checked, the park page says so instead of guessing, because "unfenced" is a claim people act on when deciding whether to let a dog off a lead. That is why some parks show fewer filters than others, and it is deliberate.
Leash law citations come from the Animal Legal & Historical Center at Michigan State University College of Law, and each is published with a note on what that statute actually covers. Most are narrower than a general leash law, and in most states the rule that binds an owner is municipal.