There are two 18 mile creeks in NY. One is a Lake Erie trib and the other is a Lake Ontario tib.
The Erie 18 mile creek is in the Hamburg/Lake View area. It doesn't have any piers at it mouth, splits into the main and south branch at 18 mile creek park and (as far as I know) isn't damed anywhere along its course. From what I've read, it has a fair run of steelhead.
The Ontario 18 mile creek is in the Olcott/Burt/Newfane area. It has piers on either side of its mouth and is damed at the town of Burt where there is a popular fisherman's park. The creek experiences significant runs of salmon and trout.
Hope that help.
