I was a young boy when the northbound bridge was built and this highway divided. At that time, nobody ever concieved of the water getting as high as it did in 2013. This cache is placed above typical high water marks, but below the historic levels we saw in 2013
While the cache is between the bridges, use your heads, park where I recomend, and cross the highway UNDER the southbound bridge. there are trails and such created by fishermen and the local wildlife.
Take your time. Throw a few rocks. Maybe try your luck with a rod..... who am I kidding? Geocachers taking time to fish?
Update: I have pushed the difficulty up a bit as it seems to be more challenging than I thought, and I have added two photos from GZ, so if you are really stuck, try using the photos for reference Also, when I went to reconfirm the coordinates, I found it easiest to hit the mark using the compass in either my phone or GPSr, so give that a try as well