Grand Traverse County Commissioners will vote on a resolution supporting Enbridge Energy's Line 5 tunnel Wednesday.
Three Upper Peninsula counties have already passed similar resolutions.
Dickinson County first passed a resolution in June, supporting the construction of a tunnel under the Straits of Mackinac to replace Enbridge's twin oil pipelines.
Iron and Gogebic counties passed similar resolutions last week.
Dickinson county commissioner Barbara Kramer said they drafted the resolution after Enbridge appeared at the spring meeting of the Upper Peninsula Association of County Commissioners.
"They're anxious to promote this and we're anxious to support it. It's hands down the best way to go."
She said Enbridge did not help with resolution language.
A company spokesperson says the support reflects what they've already been seeing in their meetings around the state.