The Great Basin
This map encompasses the mountain West’s very large
territory of internal drainage, where rivers flow into dry or saline lakes
rather than the ocean. It includes all of California and Nevada, most of Utah, and almost all of Arizona. There are also portions of Montana, a sliver of Wyoming, and bit of New Mexico and northern Mexico as well.
Small - Scale is 1:2 million or 1" = about 32 miles
Large - Scale is 1:1.5 million or 1" = about 24 miles
