T.48N. R.12W. near Amnicon Falls. Associated minerals include analcime, apophyllite, datolite and laumontite. Prehnite is found with epidote and quartz at the Wisconsin copper mine in the NE and SE sec. Prehnite is found in veins and amygdules in basalt flows at the old Chippewa copper prospects in the SW SW sec. 3 T.47N. R.12W, north of Middle River.
Associated minerals are chlorite, epidote, quartz and laumontite.
14 and SE sec. The locality is now within Pattison State Park. 8 T.47N. R.13W, west of South Range. T.44N. R.13W. west of Gordon. 35 about 1 km.