The Minnesota Department of Natural Resources reports finding more grains of gold on the surface of forested land southeast of Soudan.
The latest findings bolster the DNR Minerals Division's last report in July that surprisingly high numbers of gold grains were being found.
Gold on the surface, even when it's just tiny grains often missed by the untrained human eye, often is an indicator of gold underground, geologists note.
"This new data set strongly points towards the presence of gold within the focus area's underlying bedrock," the DNR said Friday in reporting the most recent findings. "The new samples confirm previously reported results of three samples that had high gold grain counts and create a new cluster of 18 samples that have high gold content."
The DNR is hoping a private company will use the survey results and lease mineral rights on some of the land in the area to start boring holes to see if and where the mother lode exists.
As reported in the News Tribune in July, the state has been looking in areas with state or county land where the state controls the mineral rights, with the latest cluster just south of the Eagles Nest lakes.
This is the latest data release for a DNR geological investigation that began in July 2012, within a 200-square-mile area of historical gold and base metal exploration that lies between Cook and Tower. That hardscrabble area of what geologists call "Archean granite-greenstone terrane" is covered by relatively thin layers of glacial till and sediment.
Gold from underground can rise to the surface in those conditions. The key is what shape the gold is in. Rough grains indicate it originated from a nearby underground source while smooth, well-worn grains can point to the gold being moved by glaciers, meaning the deposit could be far away.
So far, they've been finding the rough stuff. DNR officials made sure to include some cautionary fine print in their report so folks don't get gold fever too soon.
"While the identification of gold grains in glacial sediment samples may bolster the assessed mineral potential of an area, it is not a determinable test for bedrock mineralization," the agency's geologists noted. "This type of geological investigation should be considered only the first step in determining whether there are bedrock gold deposits."
The method used to find the gold grains and home in on hot spots in Minnesota is the same one used at the New Gold gold mine just 40 miles northwest of International Falls near Emo, Ontario. The mine, now under construction, expects production of about 325,000 ounces of gold and 480,000 ounces of silver annually starting in 2017.
It's been known for more than a century that gold existed in northern Minnesota rock, and several false gold rushes occurred, including in the Lake Vermilion area. But there never was enough gold documented close enough to the surface to make it worthwhile to mine.
Unprecedented test drilling in recent decades to search for copper, nickel and other minerals has revealed gold across the region - enough so that proposed copper mines are counting gold they expect to recover as part of their business plan.
Minnesota-based Vermilion Gold appears to be the only company actively searching specifically for gold in the state. The company currently is drilling test holes to pinpoint gold deposits just outside Virginia.
Gold was trading at about $1,100 per ounce Monday, below the sky-high $1,800 range of a few years ago but still far above the historical average.