Most restaurants in the US -- including mom and pop -- use national food chain networks to get the produce they use to cook with. Are there any chains that source their food locally?

Chains, by definition, are supplied by the lowest common denominator

That's something that's usually advertised by the establishment. I know that e.g. in St Louis both Rooster and Mike's Local Eats source their ingredients from local as much as possible

Infact they created their own even lower denominator because greed

Swiss Chalet in Rochester and Buffalo used to source it's potatoes locally, before they closed anyway. Kraft for everything else not supplied by the chain.

me and my 30 year old information

Five Guys usually names where the potatoes are from, but oddly don't mention the source of the beef, veggies, etc.

Not exactly. Many franchises require that you purchase food through them and some of them will put time in ensuring quality.

In-N-Out can only place restaurants in certain locations due to internal supply chain limitations. I haven't confirmed it, but I wouldn't be surprised if their food was sourced locally because of it.

And where do you think the ingredients for those items come from?

My brother is a chef at a kosher restaurant and tells me that they have to use specific suppliers. I don't know if those suppliers are 'local' but they're definitely segregated from suppliers like Sysco.

My point is there are niche restaurants, like a kosher restaurant, that may source things more locally for reasons.

It depends on the restaurant chain. The problem is that the question is if the food is local which is a harder claim to verify than if the restaurant distributes its own food.

For instance, I know that McDonald's owns its own supply chain and is really good at managing it. However, because the company serves so much food, it likely gets its food from the same locations as major supermarket chains, just with its own verification for food quality. So, the food is controlled, but it likely isn't local.