Painted Desert (Arizona) plateau's south border the Mogollon Rim, the north border of the Arizona transition zone. Owing to the strong rain shadow of the Mogollon Rim, the Painted Desert has a cold desert climate (Köppen "BWk"), with hot, dry summers and cold, though virtually snow-free winters. The annual precipitation is the lowest in northern Arizona and in many places is lower even than Phoenix. Much of the region is accessible only by foot or unpaved road though major highways and paved roads cut across the area. The towns of Cameron and Tuba City, both on the Navajo Nation, are two major settlements.
Jedediah Smith in 1822. Smith led the first documented exploration from the Salt Lake frontier to the Colorado River. From there, Smith's party became the first United States citizens to cross the Mojave Desert into what is now the state of California but which at that time was part of Mexico. On the return journey, Smith and his companions were likewise the first U. S. citizens to explore and cross the Sierra Nevada and the treacherous Great Basin Desert. In the following year, Smith and his companions were the first U. S. explorers to travel north from California (on land) to reach