It ascends the Parana to the great falls of Guayra, or Sete Quedas, and thence westward along the water-parting of the Sierra de Maracayu to the cerro of that name, thence northerly along the Sierra d'Amambay to the source of the Estrella, a small tributary of the Apa, and thence down those two streams to the Paraguay.
South of Bozeman; the Cinnabar field in south Park county; the Great Falls field in Cascade county; and the West Gallatin, the Toston and the Ruby valley fields.
The principal cities are: Butte, whose population increased from 10,723 in 1890 to 30,470 in 190o; Great Falls (1900) 14,930; Helena, the capital (woo) 10,770; Anaconda (1900) 9453.
The most noteworthy of these are the great falls of the Iguassu, near the junction of that river with the Uruguay.
The first exploration within the borders of Montana was made in 1743 by Sieur de la Verendrye, who in that year led an expedition up the Missouri river to the Great Falls and near where Helena now stands; the first exploration in that part of the state which lies west of the main range of the Rocky Mountains was made by Meriwether Lewis and William Clark in 1805.