Currency

Even though there's no national currency, it seems to me that a strict barter economy is a little infeasible considering the fairly substantial industrial base remaining in cities. There would be a common need to make wealth highly portable. Thus, precious metals. Gold and silver coins, bars, bullion, whatever. You'd get paid in a certain weight of such metals, which would translate into varying amount of paper currency or whatever depending on where you go. An ounce of gold might be $30 Cody or $50 Laurel, depending on whatever the bank of that city had decided the value would be. Thus, people would still speak of dollars, but would insist on getting paid in gold.