Hey bud,
It's not easy to find some things there because the land has been tilled so many times. I was born and raises right there in Olympia Springs. My family owned the land the springs used to be on, the have long been destroyed by government pipelines and such. There are only a few left. Growing up I remember plowing up arrow heads, cannon ball halves and things like that. There were some items that I never realized what they were I'm sure. The land around the old hotel, if it still stands, I haven't been home in years, there should be a lot of stuff maybe a little closer to where it stands or stood. The hotel was closed down after a disagreement between two gentleman and it resulted in one of the dying. My great grandmother lived to be 103 and told me many of the stories. Keep looking, speak to some of the farmers and families around there. Tell them what you are searching for. They are all very nice very humble people, I'm sure they would be willing to let you look around or show you what they have found over the years. Good luck and happy hunting!