ST. PAUL, Minn. (AP) - Sometime next year, Gov. Mark Dayton expects to face a major decision about whether a new copper and nickel mining project gets the ultimate go-ahead.

The PolyMet venture in northeastern Minnesota has been years in the planning and already has caused a rift within Dayton's Democratic Party. Dayton says he hasn't made up his mind.

In the coming week he will tour the Gilt Edge Mine in South Dakota and the Eagle Mine in Michigan as he tries to familiarize himself with the type of mining involved and its environmental track record.

Dayton says he faces a difficult decision because everyone engaged on the issue is either totally for the mine or totally against it. But he says environmental protection and economic development can be complementary objectives.