A visitor mailed the rocks back
via Snacks News
Someone sent a letter to the park with a few rocks they'd pocketed at Jenny Lake, deciding souvenirs weren't theirs to keep. Taking anything from Grand Teton is illegal — leave what you find.
A visitor wrote to Grand Teton wanting to return a few rocks taken from Jenny Lake as souvenirs. Even one pocketful adds up when everyone does it. Removing natural or cultural resources from the park is against the law, so leave what you find for the next person.