A virtual textbook of early 1860s transitional territorial borders. Colona, the pre-Colorado territorial name is shown. New Mexico is above Arizona (Baylor line). The the Territory of Shoshone is shown (pre-Idaho). Nevada's eastern border is nearly at the western edge of Salt Lake, an early effort to reduce the Mormon influence, although its eastern border is very odd. Nevada's lower tip, which would include Clark County (Las Vegas), is shown in Arizona. The map includes marvelous detail, including Indian names, forts, roads and explorers routes, mountains and rivers. It also elaborately tracks the ocean currents and sea routes. Excellent topographical detail. An essential map for western collectors.