Hopefully the local library or bookstore has a National Audubon Society book on insects and spiders, but in the meantime, perhaps someone knows off hand...
I understand that I am not giving much to go on. I saw a spider in a cave on the ceiling and it was about the size of a brown recluse if not slightly larger. It was all brown, too, like a recluse, but had white or beige bands on its legs.