Dad's Notes:  You can park in the newspaper lot if there is room or on the downtown side (North). It is quite an amazing sight - the bats leave in large unending waves, silent and just over your head. They fly within inches of trees, flowing like water around trees and obstacles. You can hear them in the bridge but not while they are flying.
     They start exiting right at sundown and continue for at least an hour. Good viewing from the grass area under the bridge, or from the bridge looking down. There is also long walking/biking trails along the river. It is a very pretty area all along the area and with downtown all lit up! You can find out when sunset is going to be by checking an online weather page like www.weather.com .