It's a Browning Citori O/U, that has clearly been there for a while. It took a second for me to break open the action and verify it wasn't loaded, and the lockup on the gun was so tight there were areas that hadn't rusted (as visible in some of my poor phone pictures.) I cleaned the mud off and found the serial number, which according to Browning's and the NRA museum's web sites say it's a 1981 20 GA skeet gun, grade I. I'd love to try and restore this thing. I think the action is probably salvageable, although the barrels are probably too weakened to be safe. The forearm wood can probably be restored, but the stock has a crack most of the way through the wrist and will have to be replaced.
From what I've found through some research, there's no way for non-LEO's to conduct an NCIC search to see if it's been reported lost or stolen, so tomorrow I'm going to call the county sheriff's office to see about bringing it in to them so they can run the check. If it hasn't been listed as lost or stolen, I have a feeling it will sit in an evidence locker for 6 months waiting for someone to claim it, and even after that I don't know if they'll let me take it back.

In the experience of the LEO's here, is there any potential reason I need to talk to a lawyer before calling the Sheriff's office? I doubt they're going to give me any grief over trying to do the right thing here, but I thought I'd ask for input.