Ounce Creek

Agate is the primary reported find, with copper, bornite, malachite, azurite, epidote, chlorite, diopside and quartz also documented from the drainage. The rock is Chengwatana Volcanic Group basalt, part of the Midcontinent Rift, which is the same volcanism behind Lake Superior agates and Keweenaw copper.

It depends entirely on the parcel. Douglas County land ownership is a patchwork of county forest, state forest, private timber and farm ground. County forest collecting policy differs from hiking and hunting access, so check with the Douglas County Forestry Department, and get permission on private land.

Roughly 1.1 billion years. The Chengwatana Volcanic Group basalts erupted during the Midcontinent Rift, when the continent began to split and flooded this region with lava. Agates formed as silica filled gas cavities in the cooling flows, and glaciers later spread them widely across the upper Midwest.

No. Wisconsin state parks do not permit rock or mineral collecting. Both parks are excellent for seeing Midcontinent Rift basalt in place, with waterfalls cutting directly through the flows, so treat them as geology viewing stops rather than collecting sites.

May through October, ideally in spring after runoff has scoured fresh gravel or in autumn after leaf fall opens up the cut banks. Black flies and mosquitoes are severe from late May through July, so bring repellent and a head net, and check for ticks after every trip.

A failed continental rift that began splitting North America roughly 1.1 billion years ago, flooding the Lake Superior region with basalt lava. It produced the native copper of Michigan's Keweenaw Peninsula and the gas cavities that became Lake Superior agates, and its rocks underlie far northwestern Wisconsin.

In the far northwest, where Midcontinent Rift basalts occur, though Wisconsin's share of the rift never produced at the scale of Michigan's Keweenaw Peninsula. Copper, bornite, malachite and azurite are reported from Douglas and Bayfield county drainages, and float copper also occurs in glacial deposits further south.

No. Wisconsin state parks do not permit rock or mineral collecting. Pattison and Amnicon Falls state parks in Douglas County are excellent places to see Midcontinent Rift basalt in place, with waterfalls cutting directly through the flows, but they are viewing destinations rather than collecting sites.

County forest land generally permits public recreation such as hiking and hunting, but rules on mineral collecting vary by county and are not the same as general access. Check with the Douglas County Forestry Department about current collecting policy before taking material from county forest ground.

By colour, which is unusually diagnostic: malachite is bright green and azurite deep blue, both as coatings, crusts or earthy masses on copper-bearing rock. Against grey basalt they are hard to miss, which makes them useful field indicators that you are in the right rock even when no native copper is visible.

Collectors describe it as genuine but low-density ground compared with Michigan's Keweenaw, and they consistently frame the challenge as land status rather than geology. Douglas County is a patchwork of county forest, state forest, private timber and farm land, and people report spending as much effort establishing where they can legally look as they spend looking. Those who enjoy it treat it as exploratory collecting in quiet country rather than a destination dig.

The recommendations split between the Lake Superior shore north of Superior and Duluth, where wave-sorted beach cobble is the classic ground, and inland gravel pits where glacial deposits concentrate material. Several collectors note that beach hunting on the Minnesota side of the lake is more productive per hour than working inland Wisconsin creeks, and that the two make a good combined trip from a base around Superior.