The Kenduskeag Stream Canoe Race. Although they are mostly focusing on Bangor, it seems, the first part appears to be the segment that goes literally through my back yard. Keep an eye out for Gumby, who enters every year and is in the first few seconds! (There are more silly costumes and canoes, too. It seems to be the fallback of the teams who realize they don't have a chance of winning.)
Ganked from ivydoor.