Four mining companies have a foothold in eastern Minnesota's resource-rich Duluth mineral complex, but if consolidation in the global mining sector continues that number could be whittled down to one.

The Duluth mineral complex, an untapped copper-nickel-platinum group metal deposit about 80 miles northeast of Duluth, Minn., currently is the subject of in-development mining projects by four exploration and mining companies: major player Teck Resources Ltd. and hopefuls PolyMet Mining Corp., Franconia Minerals Corp. and Duluth Metals Ltd.

With all four companies' deposits within a few miles of each other in an otherwise underpopulated section of the northern Midwest, the possibilities of resource sharing, joint processing and eventual consolidation are clear, sources in the region said.

"This is one of the most compact, undeveloped mining districts in the world. We're really only talking a dozen miles from one end to the other, and every time I show this to mining...