When I was maybe in 5th grade, so at least 20 years ago, I got a book from the school library that I have not seen or heard of since. The only thing I remember is that the main character (I think a boy) is looking for a missing covered wagon from the 1800s. There was maybe a treasure map involved, and I think he found it in the end, possibly concealed in a cave. I’ve searched a lot and can’t find it anywhere!
Lost Classics of Teen Lit: Name That Book! 