 Little Crow) led the Mendota in northern Dakota County, upstream to the southwest, Chief Black Dog established his village of 600 people around 1750 at the isthmus between Black Dog Lake (which is named after him) and the Minnesota River, near the present site of the Black Dog Power Plant.Following the published expeditions of explorers, in 1805, Zebulon Pike negotiated for military territory with the Mendota band which included land in Dakota County at the Mississippi River confluences with the Minnesota and St. Croix Rivers.In 1819, on what is now Picnic Island on the south bank of the Minnesota River, Colonel Henry Leavenworth built a stockade fort called "St. Peter's Cantonment" or "New Hope," where materials were assembled for the construction of Fort Snelling to be built on the bluff on the north bank.