Based on a collection of old park maps I found online, it appears that the bridge was added between the 1985 and 1986 seasons and removed between the 1994 and 1995 seasons.
However, that is based on park maps and not actual pictures of the park, so take that with a grain of salt.
1985 (Image Credit matthunterross on flickr):
1986 (Image Credit matthunterross on flickr):
and
1994 (Image Credit KitchenSlayer on flickr):
1995 (Image Credit KitchenSlayer on flickr):