From ArborWiki

The Heritage Festival is an August event held in Ypsi's Riverside Park. The Festival's apocryphal origins are in the energy crises of the 1970s - when Ypsilanti families couldn't afford gas to go on vacation, they decided to bring vacation to them in the form of an annual festival.

http://www.ypsilantiheritagefestival.com/

August 21-22-23, 2009 in Riverside Park, Depot Town, Frog Island and Downtown