Personally I don't see any indication they have been altered in any way by man. No pecking, grinding, or use wear on them. One looks like it has damage to one end but not consistent like you would see on a hammer stone.
I noticed this was your very first post - so, Welcome Aboard! Take a look at Forum: Kansas for information (i.e., clubs, etc.) directly related to your state.
If no one can identify your find - you might consider posting your pictures on WHAT IS IT? for more exposure...