Korey Atterberry wrote:

Thank you all for your help. To answer some questions and clarify, I
have an attached garage, and I ran three insulated black wires in the
trench. One wire we taped white to make a neutral. No other wires in
the trench. I now have the grounding bar I need for the subpanel.

Can anyone explain why I need to run the ground back to the main
panel, as opposed to sinking a couple of grounding rods outside near
the subpanel? These rods would be about 60-70 feet from the rods at
the main panel. Since the inspection is done I have mostly filled my
trenches, so adding another wire will be a chore, but I want to do the
right thing for safety (I guess meeting code is not as much of an
issue seeing as the original setup passed inspection...)

I would run a #8 green wire or a #6 bare wire back to the service panel
by whatever route was easiest -- just staple it to the studs and joists.
The ground wire is supposed to be run with the current-carrying
conductors, but there is an exemption for adding a ground to "old work."
#8 wire is easy to use but you're supposed to protect it from damage
with a conduit (but you could skip that if it's not gonna be inspected
and you promise to be careful never to abuse that wire ;-) #6 solid
wire is a bitch to work with, but it can legally be run without a conduit.

Bob