recently I reverse-geocoded all 170M venues in both the overture and foursquare open data releases / assigning each record a who's on first parent ID and hierarchy / there are still some open questions about how to encode and distribute the results / but as part of figuring that out I have published all the data for the US using the current working model / here: https://github.com/whosonfirst-data/whosonfirst-external-foursquare-venue-us and here: https://github.com/whosonfirst-data/whosonfirst-external-overture-venue-us