p. 741

St. Croix River, a large and important tributary of the Mississippi entering a few miles above [the] Lake Pepin, and fifty nine miles below the Falls of St. Anthony; its length is about two hundred miles. It originates in the Upper St. Louis lake where a portage of two miles over a dry pine ridge seven hundred feet high connects it with the head waters of the Bois Brule river of Lake Superior, and it is by various branches connected with the Waters of Rum river, [and] [of] the Chippewa, and the Mauvaise rivers. It is about seventy five or one hundred yards wide at its mouth, which is opposite an island in the Mississippi; and on the right bank of the river, at the mouth there is a perpendicular ledge of sand rock eight or ten feet high. A short distance above the mouth the river expands into a long narro Lake (Lower St. Claire Lake) which is thirty six miles long. At the Falls "Greenstone" rocks are found as having sometimes a columner structure resembling the famous [Giants?] Causway in Ireland. Above this point the river is filled with rapids and falls;