My 96 2wd has one. Don't know its origins, but the PO notched it for the tow hooks. So I don't know if it was a factory-installed air dam and the hooks were added later, or vice-versa. I have the window sticker; I'll update this later if I have any further light to shed.
Since LMC is mentioned above, I'll add a note about my recent experience there. They generally don't tell you the brand or origin of their parts. One might assume they are an assortment of aftermarket items, and since they're unbranded, you might even assume the worst - no-name made in China. And maybe you could be correct. I debated with myself on ordering factory tag light socket assemblies or LMC items and finally settled on LMCs. So what did I find in my LMC box? Factory tag lights! YMMV.