Enterprise does not provide them nor do they allow them to be put on their cars. I'm not sure what the heckity schmeck you're supposed to do if you get into an area where they're required. I noticed this when I rented in Reno last year, Tahoe roads often have chains required and the airport closest is Reno. I just looked and Hertz is the same.
I get why - if they come loose or you don't put them on right it can really mess up the car but I don't know what you're supposed to do if you're renting in an area that has snow.