I'll preface this by saying I've never trolled outside the Rocky for steelhead, I troll for them at Conneaut in the NE Corner of the state. But the general rules should hold true.

It's probably still to early, although you never know. Some years they show up early, some years late. As a general rule, once the lake drops below 70 F and the river drops below 60 F the steelhead might start staging outside the river mouths. And a rain event where the flow comes up can cause them to run up the river. But we never really know when they show up until some adventerous souls get out there and try for them and are finally successful. Also, I've been seeing the occassional reports for a couple months of people getting them in the rivers.

This document mainly deals with the fish stocked by PA and NY, but holds true for OH fish as well. Lake Erie info starts on page 11.
http://ncc-tu.org/published/dat/grea..._steelhead.pdf

River data for the Rocky River, including temperature.
http://waterdata.usgs.gov/oh/nwis/uv?site_no=04201500