Some of the best chert/flint forms in pockets in limestone. However, some limestone has little or no chert, while some other limestone may be loaded. Check to find out whether you can hunt there at designated times or whether the quarry pushes their chert to a scrap pile. Chert is so hard that some quarries consider it a nuisance rock and pile it aside. People managing quarry sites are usually very concerned about liability with anyone being on their site. These days somebody could go out there and drop a rock on his foot and sue the quarry for not telling him that rock is heavy. It might take a little planning to find out who to talk to. If you just drive up to their gate and ask, you might get lucky, but more than likely you will get a big NO. You might even be able to investigate through an employee. He might even have legal access to gather it for you.
WA