Where could I find a listing of state regs regarding payment of accrued vacation time at termination?

BNA used to publish a several volume set entitled "Compensation and Benefits Guide." It was terrific for these kind of state charts. In this electronic age, I don't know if they still offer it.

Panel Publishers publishes an annual volume on Mandated Benefits. Chapter 9 of that publication includes such a chart. (I have to tell you that my firm gets a royalty from that publication - full disclosure, you know.)