Here are the
boating regulations. Note that they say nothing about Mill Creek itself, just that boating is permitted only on lakes Glacier and Newport between March 1 and December 1. They don't answer Steve Z's question. And with Ken sort of egging one on, a run down Mill Creek could make for either a high point or low point of the 2020 paddling season (or both), depending on the reaction of the gendarmes! And I'm still scratching my head over legal boat lengths!