The U.S. Forest Service wants input and feedback about e-bikes on Forest Service land. Details, including forms for submitting comments, are included in the below link.
PeopleForBikes has also prepared some information to help clarify what's going on. Please check out the two following links;
The following link will allow you to see WHERE mtb trails currently are located within U.S. Forest Service property (the closest trails to St. Louis are the Ozark Trail & Council Bluff);