Most fresh water mussels (these are clams) are endangered and collecting any freshwater bivalve may have various laws or procedures that will apply in your area. Check local laws.
This is the first official 1st 'Tales From The Wasteland'. In it Dogmeat and I go over one of the lesser utilized protein sources in the wild, river clams or fresh water clams. We go over gathering and preparing/cooking them. This is a wild edible that you should never over look.