Okay, I will post what I did. As an aside, I had already finished with it before I posted it online. I called the police department and they sent out a deputy. I had done this at my parents house since mine is a shithole and would not show well if the deputy was suspicious of me (past experience with being a good Samaritan turned on me for the worst because I am upper white trash, so I was cautious). The deputy called the number on the ID and asked if the guy had lost anything else along with it. He said he had, and names an amount of money close to but less than what I had found. The guy was on his way to Orlando where he went to school, but he came back and I gave him the money. I also took him to where I found it and helped him look for the wallet it was in, but had no luck finding it. At the end he was very happy and gave me $100 as a reward for my honesty (although I told him it was not necessary and tried to give it back since I was only concerned with doing the right thing).
Not that it matters in the least, but the guy was a Lebanese immigrant. Upon hearing this, a friend told me I should have kept the money because it was probably going to terrorism--a comment I thought unkind and VERY unlikely to be true. After all, many Lebanese are Christians but get painted with a broad brush due to the region they come from, and a large amount of them fled during the Syrian occupation. I prefer not to judge a person harshly until they first give me a reason to do so. As a Christian, I feel this is the right way to be, and that I acted in accordance with Biblical teachings in the way I handled this incident.