Help with MI tide chart

To the North Georgetown / Grand Strand
1

On NOAA there are two tide charts for MI, one is 1/2 mile above the entrance to Oaks Creek & the other is the upper end of Oaks Creek. Looks to be around a 30 minute or so time difference between the two. So where is each?? I am not real familiar with the area so any help would be appreciated.

2

Entrance is the one closest to jetty or main channel, upper end is back in the creek

3

Thanks for the help.

4

GPS numbers are often listed along with the tide chart locations, punch them into google earth.